1The coming together of frames and spaces poses a particular challenge at the dawn of early modern painting. In the master narrative of the period the emphasis is customarily put on the emergence of three-dimensional space. Erwin Panofsky in his key text, Perspective as a Symbolic Form, insisted on two fundamental shifts in this process (Panofsky 1991, 27). First, objects acquire volume, perhaps under the influence of comparable changes in sculpture. Second, painters develop an ability to build a virtual three-dimensional space that becomes the primary vehicle of pictorial depth. John White noted the trial-and-error nature of this method (White 1967, 19‑56). For fourteenth century Italian artists spatiality was to some extent an ad hoc result of visual experiments, and this practice was streamlined with the introduction of mathematical perspective in the fifteenth century. This in no way simplified the complexity of the artistic process, but it moved the focus away from the creation of virtual space to its modulation. Initially painters aimed at generating homogenous depth within their work, a prerequisite of coherent immersive experience. Above all, immersion required a single dominant perspectivic register. However, hybridization of perspectivic registers was also explored.

2By hybridization I mean the combination of various orders of spatiality in a single painting. This could take essentially two mainstream forms. The painter can insert an independent segment of space into the principal register of the work. Already André Chastel noted that in the early modern period this usually happened through the depiction of mirrors, windows and images-within-images (Chastel 2020, 296‑99). Chastel’s suggestions informed the exhibition La peinture dans la peinture in the Musée des Beaux-Arts de Dijon in 1982 by his disciples (Georgel and Lecoq 1982; Georgel and Lecoq 1987). Whereas windows and mirrors traditionally complemented the principal space of the painting, even if sometimes with distortions as in the case of the Arnolfini Portrait, images-within-images had the potential to introduce fundamentally diverging forms of depth, without any link whatsoever to the primary register. A case in point for the widespread use of such imagery are cabinet paintings from the early seventeenth century, where a series of independent works, with their independent spaces, populate the walls of galleries (Marr 2010, 5‑25).

3The other possible form of hybridization was the depiction of fictive frames. The clash between the two registers was less manifest, since the trompe l’oeil frame was meant to be a real physical object outside the space of the painting. Large-scale deployment of illusionistic colonnades with twisted columns marked the Legend of St Francis in Assisi and remained a key element of the Italian Renaissance (Bokody 2015, 38‑42; Loos 2018, 61‑77). Besides murals, fictive architectural frames appeared on panels, for instance on Duccio di Buoninsegna’s Virgin and Child, today in New York (Krüger 2020, 16‑21). By the mid-fifteenth century the torn cartellino on the frame with the signature of the painter was a stock motif in Padua and contributed to the standardized market strategies of Venetian artists (Matthews 1998, 616‑48). Similar trends can be identified in book illumination (Conrad 2018, 23‑39; Herman 2020, 137‑81).

4The importance of frames cannot be overlooked in this context. They either separate the various incompatible space-segments within the work, or by the virtue of their own fictiveness, they introduce the heterogenous element itself. In the scholarly discussions around spatiality the smooth transition from the physical space of the viewer to the virtual space of the work is usually taken for granted. The boundary between these two visual realms, the frame, is supposed to be effective and invisible. Effective, so that it separates neatly the real and the painted world, and invisible, so that it does not disturb the viewer’s immersion in the latter. Starting with Jacques Derrida’s 1978 seminal essay on the parergon, this unilateral relation between images and their frames was called into question. Victor I. Stoichiță demonstrated the fundamental importance of framing in early modern European painting, particularly with reference to the emergence of the tableau, the framed canvas (Stoichiță 2015, 67‑99). Klaus Krüger extended this insight to premodern art in a series of publications, exploring the role of mediality in the devotional experience (Krüger 2001, 52‑59).

5Recently Lynn F. Jacobs examined the role of thresholds and liminality in Netherlandish painting and emphasized the anthropological aspects of frames (Jacobs 2018, 3‑19, 107‑51). She included both representations and experiences of boundaries in her work, and she highlighted in the period the constitutive role of compartmentalizing spaces. Isabella Augart investigated the reframing of embedded sacred images from the fifteenth century and its impact on worship (Augart 2019, 27‑99). Furthermore, Alison Wright’s monograph offered a convincing link between the tryouts with frames and the sociocultural perception of honor during the Italian Renaissance (Wright 2019, 103‑51). The relations between the pictorial aspects and their broader contexts (anthropological, devotional or social) reinforces the centrality of these elements already before 1500.

6In what follows, I explore some works that complicate further this dynamic link between frame and space. In all these studies, composite spaces and their segmentation is ignored or only marginally touched upon. To highlight the importance of frames, I will first turn to an example where the frame does not regulate the insertion of an independent register: the Ambassadors by Hans Holbein the Younger (Fig. 1). Jacques Lacan in an influential lecture insisted on the destabilizing impact of this hybrid system of foreshortening (Lacan 1981, 85‑89). Here, the autonomous perspective of the skull is nested within the principal perspective of the painting. Unlike in the case of windows, mirrors or images-within-images, this insert is tied to an object and devoid of a frame. As a result, it challenges and upsets the spatial system of the painting. It also upsets the comfortable and dominant position of the viewer, who is meant to be aligned with the single-point immersive space of the painting. The restructuring of these straightforward spatial correlations implies in turn the restructuring of the viewer’s subjectivity.

7In order to contextualize the radicality of this solution, I will examine Holbein’s example in relation to a series of works by Pietro Lorenzetti, Fra Angelico, Benozzo Gozzoli, Neri di Bicci, Sandro Botticelli and Fra Bartolommeo where embedded votive images are placed on or around the frame of the work. They are not mere objects; they carry elements of an independent virtual space which are at odds both with the frame and the principal perspective of the painting. The Italian painters are from the Tuscan school, and many of them are connected to the environment (the pictorial and ideological background) of the San Marco convent in Florence. They are interested in the way images can align with a religious or devotional design. They explore the same motif, that of a little panel for private devotion depicting the Golgotha, superimposed upon a larger painting, whose theme is also a sacred one. The distorted skull and the crucifix on Holbein’s painting map to this iconography and offer its personalized rereading. Ultimately, the material demonstrates the role of secondary or inserted frames in regulating the hybrid spatial structure of composite images – the way such visual orders can collapse or find new equilibrium.

Perspective without Frame: Holbein’s Ambassadors

8Hans Holbein the Younger’s signed and dated the Ambassadors [Ioannes Holbein pingebat. 1533.] behind Jean de Dinteville on the left. The figure casts a shadow over it, but it is nevertheless clear that the inscription follows one of the customary formats of early signatures, since it is depicted in foreshortening on the floor and conforms to the overall perspective of the painting. It is barely visible. That Holbein decided for a moderate mark of his artistic presence (even if it is one of the fullest by him) underlines the unusuality of the skull in the center of the work and the manner it defies its primary spatial register. The eighteenth-century sale catalogue of the property of Nicolas Beaujon (April and May, 1787) described the distorted skull the following way:

We see also a skull in perspective, to be looked at from the left corner of the painting. From the front it has the pleasure of resembling a large fish. [On voit aussi une tête de mort en perspective, à prendre de l’angle gauche du tableau, et qui a l’agrément de ressembler en face à un grand poisson]. (Hervey 1900, 10)

9The description notes several key aspects of the detail. It identifies the skull, and it establishes that this view is coherent from the left of the painting. It also proposes that it resembles to a fish noting its dual nature. The suggestion precedes and contrasts with the phallic reading made by Lacan, who wishes to see a penis in the detail, in line with the gendered reading of the plurality of the field of representation. (Lacan 1981, 88.) Unfortunately, we have no evidence for the ways Jean de Dinteville, the French ambassador to England in 1533 or his visitor, Georges de Selves, Bishop of Lavour, may have perceived the distorted object (Foister et al. 1997, 14-30). Equally, we are in the dark regarding the contemporary understandings of the interplay between the two incompatible views and the behavior they impose on the beholder, be it in London, Polisy or Paris. A transcription of Nicolas Camusat’s letters to the Godefroy brothers (1654?) certainly insisted on the skill and allure of the work. It is called “an excellent picture […] it is regarded the most beautiful piece of painting in France, by the judgement of the best painters,” [l’excellent tableau […] on tient ledit tableau la plus belle pièce de peinture qui soit en France, au jugement des meilleurs peintres]. Yet the reason for this appreciation is not specified (Hervey 1900, 19). Although formulaic in its exaggeration, the sentence acknowledges that the work may have been accessible to painters in the seventeenth century.

10The sales note, on the other hand, adopts an ambiguous terminology and calls the detail a “skull in perspective.” It is ambiguous, since the entire painting is depicted in perspective, conforming to the rules of renaissance foreshortening. The protagonists, the globes, the instruments of music and navigation, and the geometric patterns of the tiled floor are all “in perspective.” Together they create the immersive three-dimensional space of the painting. The skull questions the unity and coherence of this primary perspective by introducing its secondary perspective. The primary spatial register of the work is taken for granted, which allows the secondary register of the skull to appear unique and extraordinary.

11Research on Holbein’s Ambassadors insisted on the dual source of this pictorial solution. The iconography of the Golgotha and the symbolism of Vanitas presumably served as models for the detail, which becomes the reminder of death, memento mori, in the work (Foister et al. 1997, 44‑57). There is a crucifix in the top left-hand corner of the painting. Dissociated in Holbein’s composition, it nevertheless recalls the countless representations of the Crucifixion with the skull buried at the feet of the cross, and perhaps the retake of this motif in some early 16^th-century portrayals of Saint Jerome in his Study (Foister et al. 1997, 55‑57). Also, despite their separation within the painting, some visual links between the two components remain. The crucifix is placed above the spectator if they are looking at the skull from the left (recommended by Nicolas Beaujon); and it acquires a quasi-frontal view above the skull if it is observed from the right. Holbein appears to rely on the traditional Christian repertory of death and redemption, but at the same time he dismantles and reconfigures its basic elements.

12Furthermore, the integration of two incompatible systems of perspectives can be seen on a contemporary woodcut of Emperor Ferdinand by Erhard Schön (1531‑34) and a slightly later portrait of Edward VI by William Scrots from 1546 (Bolland 2018, 95). The process, later to be known as anamorphosis, was included in manuals for painters already in the sixteenth century, such as Daniel Barbaro’s La Pratica della Perspettiva (1569) (Baltrušaitis 1984, 15‑36, 91‑112; Kemp 1990, 50). Barbaro calls the process a “beautiful and secret part of perspective,” and connects it even to mirror writing, reflections of light and refractions of objects in water. His explanation underlines the importance of the correct viewpoint:

If the eye that beholds [the detail] is not positioned in the determined spot, any other thing will appear but the one that is painted. And then, from its viewpoint, it shows that which has been in fact depicted according to the intentions of the painter. [Se non è posto l’occhio di chi le mira a neel (sic) punto determinato, ci appare ogni altra cosa, che quella, che è dipinta, che poi dal suo punto veduta dimostra quello, che è veramente fatto secondo la intenzione del pittore]. (Barbaro 1569, 159)

13Barbaro’s description is slightly misleading, since it suggests that the anamorphic object will present a coherent view from the primary register of the painting as well. However, this is not the case with the skull on the Ambassadors, and not even Scrots’ anamorphic painting (Fig. 2) conforms to that rule. He effectively negates the primary – frontal – view of the work and forces the beholder into a fixed position on the side. Holbein’s more nuanced approach consists of the difficult balance of the two discordant registers. The portrait is plausible from the front, the foreign tissue of the skull does not destroy the overall illusion of the painting: it simply questions and destabilizes it. Furthermore, Scrots frames his work with a white circular line which encompasses the portrait and the brown ground of the inscription. This frame affirms yet again the independence of the embedded unit from the rest of the painting. The most ambiguous part is the green foliage of the forest – a quasi-abstract pictorial surface that is credible from both viewpoints.

14The absence of the frame in the Ambassadors is part of the compromise between the two dissenting perspectives. Holbein violates the unity of space, or at least the unity of viewpoint, but he does not position the skull as a fully independent pictorial unit with a bespoke frame. This is particularly clear in the ways the grey outlines of the skull are superimposed on the sharp geometric pattern of the floor, reinforced through its partial shading. The contact zone between the two areas emphasizes transition as opposed to a clear-cut boundary, painterly values dominate the contours instead of linearity. The detail morphs into the painting rather than being incised into it.

15One can only speculate about the underlying patronal or artistic intentions to dissociate the skull and crucifix in the space of the painting and to assign a different perspectivic register to the latter. Amidst the political and religious turmoil of Henry VIII’s court, Jean de Dinteville was becoming more and more tired of his assignment: “I assure you very earnestly that I am the most melancholic, weary, and wearisome ambassador that ever was seen. [Je vous advise bien que je suis le plus melancolique fasché et fascheux ambassadeur que vistez oncques]” (Hervey 1900, 80).

16The reference to melancholy might justify the insertion of the skull as memento mori, a personal reflection perhaps on the emotional state of the commissioner. The separation from the crucifix reinforces the human dimension of the feeling, since the customary Christian resolution of the conflict is downplayed. Holbein’s anamorphic treatment of the skull is certainly plausible as a purely pictorial bravura, but it is also comprehensible in the context of this effaced reference: the reminder is there but it is distorted.

17The originality of Holbein’s work has been widely noted, and I have no intention to question this premise. In what follows I plan to explore some earlier Italian examples by Tuscan painters ranging from the oeuvres of Pietro Lorenzetti to Fra Bartolommeo, where quasi-independent fictive panels of the Crucifixion are inserted into altarpieces. With more or less intensity, the embedded images referred in all cases to the Eucharist in the context of the altarpiece, and probably to the elevation of the host as well. In this respect, the Crucifixion panels display the canonical Christian message of death and redemption (often with a miniature skull), which is present also in the crucifix in the Ambassadors. The Italian examples constitute an unusual form of images-within-images, where the secondary work remains to some extent separate from the primary one, despite being depicted on the same surface (Bokody 2015, 89‑139). The tension between the principal and embedded element is resolved in a different manner: whilst foreshortening is limited, the tangible presence of the frame is palpable. Direct derivation between them and the Ambassadors is unlikely, even if Holbein’s trip to Italy remains a prevalent hypothesis, supported by the permission of Basel’s city council to sell “his works to foreign patrons in France, England, Milan or the Netherlands” (Bätschmann 2001, 48‑49). Nevertheless, they engage with similar motifs and pictorial problems despite their differences, and their comparison adds to the perception of space and frame in the period.

Embedding Crucifixes: Pietro Lorenzetti and Fra Angelico

20These absences are important since they work in favor of the current strong contrast between the embedded votive image of the Crucifixion and the principal composition. With an intact original frame and its imagery, this contrast would have been less stated. Nevertheless, it persisted in all probability. Accepting that our understanding of the original composition is bound to remain incomplete, the following aspects of the work can be noted. Fra Angelico abandons the traditional gold ground for the principal image. The Virgin and her entourage are situated in the clearing of a forest by the sea. The natural setting reinforces the three-dimensional space of the painting that extends beyond the heavenly court. On the other hand, the embedded Crucifixion panel adopts without ambiguity or hesitation a two-dimensional gold ground. The clash between these two visual registers materializes therefore as a contrast between space and plane, and between naturalism and traditional material symbolism.

21Furthermore, in terms of its positioning, the gold ground is set against the intricate details of the Anatolian carpet that structures the principal image. The geometric patterns of the carpet belong to the same two-dimensional register as the gold backdrop of the Crucifixion, since they also lack depth. Yet, they are different, since despite their flatness they become the vehicles of the linear perspective of the entire painting. The carpet, devoid of foreshortening, is depicted in foreshortening. The Crucifixion, largely devoid of foreshortening, is placed outside of the three-dimensional register of the work. The play between the carpet and the embedded image extends to the neutral sandstone ground of the courtyard. This plane surface differs from the geometric patterns of the carpet in perspective and from the limited visual world of the Crucifixion – it effectively offers a baseline for both.

22The only elements of spatiality in the embedded panel are the limited corporeality of the three figures and the modest hill of the Golgotha. Here, the skull refers explicitly to the link between sin, death, and redemption, which justifies its integration into the overall iconography. Fra Angelico would like us to believe that we see a smaller, more traditional panel painting in front of his stylish and up-to-date altarpiece. The difference between the two registers is present in terms of the ground and the use of perspective, but just to be absolutely sure, the painter consolidates it further with a molded frame, also in gold. It is not overtly ornamented, but the layers and relief-effect of its molding delineates a clear division between the embedded and the principal image. In sum Fra Angelico uses his pictorial repertory to insert a fictive image into another. In this process, he insists on the difference between the primary and secondary pictorial registers, and ground, perspective and framing are all subordinated to this aim.

23The pictorial contrast reinforces theological distinctions and devotional function. It supports the temporal divide between the Virgin and Child in the principal composition and the death of the Savior on the Golgotha. The dying body on the cross is recorded as a historical event as opposed to the real – heavenly and eternal – presence of Mary and the child Christ in the panel. The devotional reception of this distinction is more complex. Whereas the ceremonial décor of the heavenly court clearly befits the self-promotion of the Medici-patrons, the Crucifixion panel acquires stronger sacred dimensions by virtue of its simplicity and archaism (Krüger 2020, 22). It becomes more the image to be venerated than the altarpiece that contains it.

Separation of Registers: Benozzo Gozzoli

24Further retakes of the motif in the work of Benozzo Gozzoli confirm these objectives. Even if Giorgio Vasari’s assertion that Gozzoli was Fra Angelico’s disciple can be questioned, their decade-long association in Florence, Rome and Orvieto is generally accepted. Gozzoli presumably worked on the San Marco Altarpiece, some of the figures around the Virgin’s throne are attributed to him (Ahl 1996, 6‑12).

26The fictive Crucifixion panel is depicted in front of the fictive predella. It has a white plaster molded frame, devoid of ornament, which distinguishes it visually from the overall frame of the work. It is marginalized in terms of its position, since it barely intrudes into the space of the fresco, only the top part of the frame overlaps with the rim of the tiled floor. The clash between the primary and secondary perspective, characteristic of the San Marco Altarpiece, is missing. Nevertheless, here also, the panel is devoid of any depth. The Crucifixion group and the figures of Saint Augustine, Nicholas of Tolentino and the Augustinian friar Domenico Strambi have some corporeal volume, but they appear in front of a flat turquoise background. Space is only indicated through the rocky terrain around the cross. This ground was used also on the medallions of the predella. Furthermore, Gozzoli emphasizes the separate material reality of the fictive panel. The work is slightly tilted, the composition suggests that it was placed on the altar in front of the predella. Its frame casts a fictive shadow onto the predella and its simulated wooden base on the right.

28It appears that Gozzoli relied on the visual distinction originally developed by Fra Angelico for the San Marco, however, he transforms the theological contrast between the presence of the Virgin’s heavenly court and the temporal event of the Crucifixion. It is used here to link a biblical (death of Christ) and a hagiographic (martyrdom of St Sebastian) event to each other. The former is certainly the model for the latter and, in devotional terms, the Crucifixion aligns with the supplications addressing the saint.

29The embedded panel appears once more in Gozzoli’s oeuvre, originally in the roadside tabernacle between Castelfiorentino and Meleto. The shrine (Fig. 3) was dedicated to the Madonna della Tosse; Gozzoli signed and dated it on Christmas eve in 1484 (Ahl 1996, 212‑13). The commissioner, Messer Grazia da Castelnuovo, was the bursar of the churches in Valdelsa. For safekeeping, the ensemble was detached in 1970 and in 1987 it was moved to the communal library in Castelfiorentino. Archival photographs taken during the restoration document the original arrangement, and they can be used for evaluating the spatial contexts of the San Marco Altarpiece and the Saint Sebastian frescoes. The fictive mural altarpiece operates with various layers of illusionism, all simulated. The central piece has a classicizing architectural frame that rests on a predella. The frame consists of a richly ornamented external unit and a more modest brown internal molding. Five angels are unveiling this altarpiece by lifting up a lavish drape. Within this two-tier visual discourse, Gozzoli inserts a further work. A small-scale gabled panel of Christ (Fig. 4) is placed on the predella. The work adopts the compositional arrangements of the icon, it is a close-up of the Savior’s face, which limits the possibility of spatial experiments. Here, the principal image itself is devoid of a deep space, only Saint Paul steps onto the inner molding of the fictive architectural frame. In all probability, the restricted spatiality of the central image was meant to reinforce the illusionistic appeal of the unveiling. The Christ panel fits into this arrangement: it highlights the fictive material presence of the altarpiece. Its carved frame and cast shadow serve the same purposes. It is shifted to the left from the central axis, which adds an ad hoc character to the composition, as opposed to the vertical rigor of the previous works.

In and Out of the Frame: Neri di Bicci, Sandro Botticelli and Fra Bartolommeo

30Benozzo Gozzoli was not the only painter who may have been inspired by Fra Angelico’s Crucifixion panel on the San Marco Altarpiece. Similar solutions appear in the works of Neri di Bicci, Sandro Botticelli and Fra Bartolommeo. Neri di Bicci’s Coronation of the Virgin (Fig. 5) can be dated to the 1470s on the basis of stylistic considerations (Zeri 1976, 87; Thomas 1997, 104). The work is unusual in the sense that for the principal scene the painter experiments with the combination of a flat gold ground and the three-dimensional corporeality of the figures. The angels and the kneeling saints are placed outside of the vortex of this medallion, resulting already in a hybrid spatial composition. Placed in the central axis and flanked by two angels, a fictive wooden panel of the Crucifixion is located in front of the main composition. The Crucifixion has a flat gold ground as well, spatiality is limited to the figures and the hill of the Golgotha with the skull. Mary’s attire (red robe with a blue and yellow mantle) retakes Christ’s dress in the center, whereas John’s dark robe and red toga have their counterparts in the clothing of the kneeling nun and St John the Baptist.

31Although the molded frame with a cornice separates the embedded detail from the rest of the work, Neri di Bicci in fact brings closer the style of the Crucifixion panel and the Coronation scene. Besides the pictorial interest of combining different spatial registers, there may have been liturgical considerations behind this decision. As it has been noted, the section with the panel and the angels was cut and reattached with hinges to provide a door for a ciborium (Zeri 1976, 87‑89; Ronen 1988, 116). Since the intervention does not follow the boundaries of the fictive panel, any strict correlation regarding functionality should be treated with caution. However, if the link to the ciborium is hypothetically accepted in the context of the original setting (which is unknown), one may wonder at the way the gold ground and shape of the medallion in the center recall a paten. This shared eucharistic reference could explain why here Neri di Bicci aligns the principal and embedded images instead of markedly distinguishing them, in support of the homogenous devotional experience of the work.

32Sandro Botticelli’s Bardi Altarpiece for the Santo Spirito in Florence (Fig. 6) is closer to Fra Angelico’s and Benozzo Gozzoli’s works: it maintains the contrast between the highly naturalistic setting of the sacra conversazione and the reduced presentation of the Crucifixion. The account book of Giovanni de’ Bardi preserves records that Botticelli was paid seventy-five florins for the panel (of which thirty-five was specifically for his brush) in August 1485, whereas Giuliano di San Gallo received twenty-three florins for the frame already in February (Blume 1995, 173, 183). The client, Giovanni de’ Bardi was a member of the Medici Bank in London from the 1460s to 1483 and sent his nephew Adriano di Bernardo to school in England (70‑71).

33The earlier completion of the carpentry means that Botticelli was aware of the features of the frame whilst finalizing his panel, therefore he could take its physical aspects into account. The Virgin and Child occupy the middle plane of the composition, and St John the Baptist and St John the Evangelist stand on a sandstone step or pavement in the foreground. This part is slightly elevated and props up the Crucifixion panel, which is thus positioned in the liminal area between the real frame and the virtual space of the garden. The molding of the sandstone pavement repeats the molding of the wooden frame below and creates a visual transition from the outside to the inside of the painting. The embedded image inhabits this no man’s land. Besides its gold frame with a cornice, the dark ground of the fictive panel strongly highlights its independence. Botticelli paints a negative space that rejects any implications of foreshortening and stands in stark contrast with the warm color palette of the rest of the work. Against this dark background, the cross, the body of Christ and the hill of the Golgotha (without the skull) appear as a silhouette. The minimalism of the pictorial execution emphasizes Christ’s body, which has additional eucharistic references (Jászai 2010, 280). Behind the fictive panel there is a lidded vessel, which looks like a pyxis, a container for the consecrated host (Fondaras 2005, 17).

35The Crucifixion follows the generic iconography of the subject, with the Virgin Mary and St John the Evangelist flanking Christ’s body on the cross. The color scheme of the figures is vivid, Mary’s red robe and green mantle essentially repeat the attire of the apparition, with the difference that there the green is restricted to the inner lining. John’s and Barnabas’ red togas are also similar, but the former wears a light blue tunic. The intensity and comparability of the colors indicate that Fra Bartolommeo adopted the same pictorial idiom for the embedded image as was used for the principal one. This convergence marks also the handling of space, since the landscape and blue sky behind the central group of the Crucifixion offer a deep and infinite vista that is identical to the background of the main scene. Fra Bartolommeo is confident that the thick molded frame of the portable altarpiece prevents any conflation of the two spatial registers, therefore they can be equally nuanced. In addition, the dark tones and relative flatness of the foreground reinforce the isolation of the nested image and avoid the conflict between the two different orders of perspective. In the end, his two readjustments, the integration of the fictive panel into the overall spatial composition and its detailed virtual space, result in taming the pictorial as well as devotional difference of the motif. It is on its way to becoming an object among objects in the work.

Conclusion

36The Italian examples relied on the motif of embedded panel paintings to introduce visually distinct secondary registers into the works for theological and devotional purposes. Nevertheless, the strategies can be different. In the case of Fra Angelico, there is a tension between the geometric patterns of the foreshortened carpet and the minimal inner depth of the inserted unit. An archaic sacred panel is contrasted with the vision of a modern heavenly court. Benozzo Gozzoli uses cast shadows to indicate the boundaries between fictive pictorial entities that are clearly separate and references the temporal links between biblical and hagiographic events. Neri di Bicci aligns the archaizing embedded and the principal registers within the composition to underline liturgical function, whereas Fra Bartolommeo similarly coordinates their up-to-date style, which dilutes its devotional variance. On the other hand, Sandro Botticelli makes the fictive Crucifixion panel as different from the rest of the altarpiece as possible. Regardless of whether the secondary perspective is reduced or amplified, the works are all carefully framed, and the painters also explore the possibilities of positioning these fictive details vis-à-vis the actual physical border of the works. The result of these decisions is the enduring hierarchy of the primary and secondary pictorial registers in heterogenous paintings.

37Holbein’s rebellious move consisted of reversing this distinction. His readjustments went against the compromise of his Italian forerunners. The skull is no longer an auxiliary of the crucifix. A fully diverging supplementary perspective is developed that results in the distortion of the object. At the same time there is no frame that would contain this experiment. In this process, he achieved a new and dynamic balance of the primary and secondary registers, whereby their hierarchy is questioned and contested. The dynamic balance here questions the ceremonial representation of the ambassador and his guest without fully overwriting it. The skull becomes a nuanced expression of the patron’s melancholy and a commentary on his self-fashioning.

38Holbein’s pictorial proposition could also shed new light on the reception and devotional role of the embedded Crucifixion panels in Italy. Although in these panels the conflict between the perspectives is compartmentalized through the use of frames, the heterogeneity of the works remains. Like Holbein’s skull, the inserted panels do challenge the straightforward spatial and iconographic structure of the principal composition, but this challenge is instantly rationalized in the overall arrangement. However, traces of the tension persist, since the foreign tissue of the image-within-image is not fully effaced, and hence the beholders have to divide their attention between the different religious registers. In this sense, one may liken the destabilizing effect of these details to the operation of dissemblance, particularly in the context of the San Marco. Georges Didi-Huberman suggested that the fictive marble boards below the fresco retake of the San Marco Altarpiece in the corridors of the monastery contrast dissemblance, the absence of figuration, with the prevailing aesthetics of resemblance (1995, 49‑56). Certainly, the gap between figuration and absence is wider than between representational registers. Nevertheless, Fra Angelico’s pictorial (and theological) sensitivity could explain the search for composite works and the careful framing of their hybrid spaces.