• 1 ILS 102= CIL II 4701 imp. Caesar divi f. Augustus cos. XIII, trib. potest. XXI, pontif. max. a Baet (...)
• 2 Romm, 1992; Roller, 2005.

1A famously eloquent milestone proclaims the rebuilding, in 2 B.C., in the name of Augustus, of a Spanish road ‘from the Baetis and the Ianus Augustus to the Ocean’.1 The Baetis is the Guadalquivir, the great river of Andalucia, after which provincia Baetica was to be named. In this context, Oceanus must be another, less familiar, river, the circumambient stream which, in Greek thought from Homer onwards, bounded the dry land of the inhabited world.2 All rivers were, in mythical language, the divine offspring of Ocean and Tethys the inland sea, 10,000 strong, in the estimation of Acusilaos of Argos, in the early fifth century (FGH 2).

• 3 For all these themes, see Holland, 1961.

2The rhetoric of the milestone is readily interpreted. First, it celebrates Rome’s road-building power, and it does so in part through the evocation of the very Roman deity of doors, crossings and beginnings, Janus, linked in the titulature of the monumental gateway which bears his name at Corduba, principal Roman colonia of the province, with the pontifex maximus, Augustus, himself. The road therefore had a formal entrance, of the same kind as the arch which survives today marking the terminus of the Augustan rebuilding of the Via Flaminia at the colonia of Ariminum (ILS 84). The Ianus of the Spanish road was also probably part of a different crossing, a bridge across the Guadalquivir itself.3

• 4 The new fragment of Artemidoros of Ephesos, in which the springs of the Baetis mark the Roman provi (...)
• 5 Other examples of Augustan river-thinking: Rhenus, Tanais, Danuvius and Albis the rivers of Res Ges (...)

3At the same time, the inscription has a geographical register, from which the road-building cannot be separated. It is measured from river to river, from the river which gave its name to the province to the River which surrounds the world. The Roman road is written on a landscape whose other features are those of the common literary and learned tradition going back through Hellenistic geography to Homer.4 The Spanish milestone is thus a very striking document of Augustan hegemony and its ideology, an exhibit in a rich display of Augustan consciousness of the rôle of rivers in the landscape, found in both the literature and the documents : the river and the road resemble each other, and both are drawn into the ambit of Roman organising and interpreting power.5

• 6 Modern discussion of the theme is especially indebted to Nicolet, 1988: e.g. p. 232 n. 20: ‘dans la (...)

4The present paper aims to explore further this contribution of rivers and their conceptual geography to imperial ideology, and to trace something of its genealogy before and after Augustus.6 But its second and less familiar aim is to address the problem of how to reconstruct the discourses through which ideas of this kind were received, understood, and re-circulated, a neglected dimension in the history of ideas. Scholars (and I do not except myself) have been content with a schematic doxography which inclines to support essentialising views of the identity of Romans and subjects, rather than concerning itself with interactions and their complex modalities. Since Jean-Marie Pailler has written so eloquently on the religious registers which are among the more visible to us of the media through which rulers and subjects encountered each other’s ideas, has elucidated the cognitive landscapes of subjection and resistance across Republican Italy, and has made a special contribution to the study of the environmental consciousness of the inhabitants of the Gallic provinces, it is a great pleasure to be able to contribute this study to a volume in honour of a scholar of outstanding versatility and originality.

• 7 Braund, 1996.
• 8 Campbell (2012 forthcoming) will provide a benchmark for the study of rivers in Antiquity.

6When we speak of a discourse or a rhetoric, however, we must try to characterise the users of the system in question : which people spoke how, about what, over what time-span - and who was listening ? An imperial or an administrative discourse is a social reality, not just an abstract strand of the history of ideas. It is worth pursuing the notion of a Roman ‘environmental psychology’, but of whose psychologies are we actually speaking ?7 Using rivers as markers in the geography of power was more complicated than the easy literary antecedents of the Spanish road suggest. Wider reflection on the uses and meanings of water in the ancient world can help offer an alternative approach to the place of rivers in Roman conceptual geography. The history of Roman hydrology can be employed to interrogate the evidence for the working of the early imperial state, and lead to a rather different conclusion from the conventional top-down model : a ‘users’ view’ of the environment on which, alongside natural philosophy and administrative symbolism, the ‘learned schema’ also depended.8

• 9 Strabo 7, 2, 13 is the first clear statement of the unity of the Danube: a useful treatment at Nico (...)

7The ten thousand children of Okeanos and Tethys punctuated an enormous world, establishing its scale and texture with their enormous number. They also joined it up conceptually. Two strategies are especially important, which could be thought of as lateral and lengthwise. Through the first, such a great number of subdivisions evokes a fragmented world composed of abutting lands bounded by rivers, so that the totality of the land is envisaged as a tessellation, and every river joins two territories. But the really long river, as it flowed through inevitably differentiated spaces, joined up many regions and helped imagine their contiguities and overall sequence. Identifying the headwater and the source, and mapping them onto the mouth, involved understanding the inter-relationship of regions and the scale of continents. So rivers functioned also as a real guide to the layout of unfamiliar spaces, and could be imagined as doing so on a scale which took them into the speculative and the imaginary. We are inclined to laugh : but one of these improbable linkages, that of Danube and Ister, turned out to be true.9

• 10 Briant, 2002 (for hydraulic demonstrations of power in west Asia); Harmansah, 2007.

8In this geography, the wonderful had a significant role. Rivers were among the extraordinary manifestations of Nature, and took their place in Antiquity in the thaumatic geography through which Nature was comprehended. Remarkable for their size and power, rivers also exhibited numerous special features, from variations in their annual regime to underground tracts or waterfalls. They were thus an inviting yardstick against which to measure human might and attainment. Great rulers in particular have been apt to respond to riverine challenges, so that the control and imitation of rivers and their features is a large topic in cultural history in its own right : we need look no further than Herodotus’ account of west Asia to see that.10

• 11 Especially Fales, 1995; more generally, Liverani, 1995; Milano et al., 2000.
• 12 Briant, 2001, p. 114 (on problems with how the text presents the Euphrates).
• 13 Thus already Whittaker, 1995

9The Neo-Assyrian empire bequeathed orientation around rivers to the toolkit of imperial geographers.11 The Euphrates occupied a peculiar position in the conceptual geography of power. It served as a marker to distinguish the Mediterranean zone from the Assyrian core. For all that the tract of its course which does that best, around Zeugma and Carchemish, is relatively short compared with the long course of the river through the Syrian desert, ‘over the river’, Ebir Nāri in Akkadian or Aber Naharā in Aramaic, designated an important part of the imperial periphery, which was different in kind from the heartland. This differentiation is not inevitable, but formed an important part of the legacy of this way of thinking. Neo-Assyrian and Achaemenid ideas of two worlds divided by a river were clearly understood by their Greek and Roman successors. The priests of the temple of Apollo at Magnesia on the Maeander set up a text purporting to be a letter from King Darius to his slave the satrap Gadatas, praising him for naturalising on the other side of the River the crops characteristic of Achaemenid Babylonia. The text is almost certainly a complete fabrication of the early Roman imperial period, but ipso facto becomes an eloquent document of the consciousness of that age and how it imagined rivers as cultural termini.12 Archaeology repeatedly shows that rivers did not act as cultural boundaries, but that did not much alterthe prevalent imaginaire.13 At the same time, more distant rivers served to delimit the vast extent of monarchic power : it was said that the Persian Kings kept phials of Nile and Danube water in their treasury as a sign of the extent of the Empire (Plut., Alex. 36).

• 14 Lepore (1977) for rivers in Greek colonisation, with Coarelli, 1988 for the Italian situation. Purc (...)

10For the traveller by land, rivers in sequence help weave la trame du monde, but they also shape the land as seen from the sea, pinpointing the journey of the mariner past their outfalls. The late Classical author we call Pseudo-Skylax makes ‘joined-up Greece’, he Hellas syneches, start at the Gulf of Ambracia, defining a region which extended as far as the river Peneus in the vale of Tempe, at the city of Homolion in Magnesia ([Skylax] 33). This is the river-thinking of the periplous. The Peneus and the Ambraciote gulf are landmarks on the coastal voyage - though for the important role of bounding Greece, quite resonant markers have been selected. This is the perspective which deployed the river to name and reference the destinations of Greeks overseas. The transfer of cult was an element here : as Acusilaus saw, these rivers were divine. River-names helped transfer the topography of home to alien settings (as with Sybaris or Siris, both named after Achaean streams) or pattern the world with mythological resonances (such as the various uses of the name Eridanos) ; in turn this is probably to be seen against the background of the importance of rivers in the early geographic consciousness of Greek culture.14 But it is important that imported and appropriated hydronyms jostled in an apoikic landscape to which rivers contributed, as harbours and as routes up country away from the new settlers’ maritime element, thus shaping practical and economic relationships between settler and local.

• 15 On the environmental links of the later rural tribus: Purcell, 1996, p. 201. Romans sometimes impos (...)

11From the early fourth century, Roman administrative practice seems to have related to the environment in ways reminiscent of these practices of the Greek apoikiai.15 Roman city-founding in the third and second centuries certainly used hydronyms : on the Campanian coast, for instance, the post-Hannibalic coloniae at Liternum and Volturnum were named for the outfalls of the Regi Lagni (better known as Clanius than Liternus), and the Volturno. The laying out of the Via Valeria from sea to sea across the mid-point of Italy, joining the Tiber to Ostia Aterni, seems to anticipate the Augustan learned schema.

• 16 The definition of the zone within the ring of 100^th milestones in administrative law of the imperia (...)
• 17 The usage of ‘upper’ and ‘lower’ seas for Adriatic and Tyrrhenian is parallel.
• 18 Priscian, Gram. III 38, 28 cis… magis localem habet significationem ut Cisalpina Gallia et cis Rhen (...)
• 19 As the passage of Livy on 211 B.C. quoted below confirms. Some other cases: Cicero, Att. 7, 2, 6 (5 (...)

12Even joined-up Greece lacked a true centre : still more the diaspora Greece of distant Mediterranean coasts. Rome was different, and the articulation of the city of Rome as conspicuous conceptual centre is well-known. With it went a whole geography of proximity and distance which finds only faint precedents and parallels in Greek practice. The relational terminology of Nearer and Farther, best known to modern geography in labelling parts of Asia, was fundamental to Roman conceptual space. It divided the world into concentric circles around Rome, measured, in its developed form, by markers on the radial roads which formed the passages away from the centre into the remoter reaches of the world.16 Sometimes the inner core was Italy, and beyond, further, lay the provinces across the twin boundaries of sea and mountains, the transalpinae and transmarinae provinciae ; the provinces themselves, as in the case of Spain, were conceived as citerior or ulterior ; indeed the whole vocabulary of cis and uls became a largely specialized language for expressing the geography of proximity.17 The grammarians concluded that this usage of cis was very specialised, and what survives of Latin literature certainly confirms.18 Cato’s description of the ager Gallicus as ‘cis Ariminum’ (Cato, Orig. fr. 43) is the first case, but the existence of quinqueviri cis and uls Tiberim (Digest 1, 2, 2, 32) attests the thought-pattern even earlier.19

• 20 See also Festus 232 L. Ancient Rome was not, of course, ‘built on the Tiber’, and did not span the (...)
• 21 Purcell, 1990a. For the Po in the definition of a quaestorian provincia, Plutarch, Sert. 4, 1.
• 22 Richardson, 2004.

13Rivers were very helpful markers in this topography of relative distance. They might serve as markers tout court, convenient but arbitrary lines for separating further and nearer. But they might indicate real political and social differentials. The idea that the other side of the river is importantly different underlay the view that Etruria began in Transtiberim : ‘here we are fenced in by the Etruscan stream’, as Evander put it in the Aeneid (8, 473 hic Tusco claudimur amne).20 Further afield, the Po had a special place in the emergence of Roman administrative praxis. The coloniae of Placentia and Cremona were designed to bring Roman settlement to this major geographical marker, and the building of the Via Aemilia consciously transformed the whole Cispadane region into a distinctively Roman landscape, which could be distinguished from the different world beyond the river, even though the expansion of both Roman road-building and of the foundation of new settlements across the Po was not long delayed.21 The development of the vocabulary of cispadane and transpadane with their changing cultural and organisational implications is an important chapter in the history of this subject. An heir is the puzzling Transduriana provincia of the Tabula Paemiobrigensis.22

• 23 An intriguing parallel: Dionysius 1, 9, 2 the Aborigines and Pelasgians founded a state bounded by (...)

16Here is extensive use of the technical diplomatic and institutional vocabulary of cis and trans. It sets up a grid across the whole of west central Italy - using its rivers. It does not employ any other regional terminology, except for its reference to the three individual territories of Nepet, Sutrium and Veii. These rivers, the Tiber, Liris and Volturnus, are - remarkably - used to calibrate the intensity of the exilic displacement to be inflicted on the Campanians.23

• 24 Note also the choice of another type of hydronym for the colonia of Puteoli, suppressing the striki (...)

18River-thinking and its congeners are no innocent evocation of the world of Nature. The recourse to that world is intended to deny Culture. The type case is the iconoclastic revolutionary spirit of the Law of 22^nd December 1789, abolishing the regional loyalties of feudal France with the new nomenclature for the départements, ruthlessly devoid of human associations, all deriving from the physical geography of mountains, forests and, especially, rivers (an earlier proposal had been simply to employ numbers). Such naming is, then, very familiar to us, but it deserves comment when the Roman state is observed adopting this strategy. Choosing names of natural features was less fraught with the loyalties of local identity than the traditional and more socially oriented names of villages, fortresses or cities. River-geography was here used to chilling effect to make orders and arrangements from on high, displaying the disposing power of Roman authority and its Olympian detachment from mutable human concerns.24 Only a very great state, says the message, could think in this global, and nature-based, manner about the peninsula which was its homeland too.

• 25 Raj, 2003, p. 51 against the pre-colonial terra incognita.
• 26 The quotations is from Markovits et al. 2003, 7. See also Edney, 1997.
• 27 Markovits et al. 2003, p. 14.

19Ancient authors, like ideologues of other era, are quite happy to represent the objects of conquest as a tabula rasa, as terra incognita. It has been usefully demonstrated in a parallel modern colonial context, the recent history of conceptual geography and European colonial power in south Asia from the eighteenth century.25 The outsiders’ use of surveying and the imposition of map-oriented institutional dominance has been called part of ‘an imperialism of categories, imposing new rigidities on a pre-colonial world which was characterised… by a large degree of fuzziness’.26 An attentive reading of the documentary evidence shows, however, that indigenous surveying and local knowledge were involved by European administrators in the process of institutional innovation from the start, so that the resulting system, though indeed oppressive, can by no means be seen as the simple imposition from the outside of a wholly alien way of thinking - rather the relationship has been vividly characterised as ‘asymmetrical reciprocity’.27 And under even as absolute an imposition as the 211 proposals, negotiated relationships and complex human landscapes underlay the brutal geographies.

• 28 Pol. 3, 37, 8; 3, 39, 8, therefore of 118 ‘one of the last things he ever wrote’, Walbank ad loc.

20As the provincial empire developed after the late Republic, the geography of proximity (citerior and ulterior) was replaced in southern Spain by a similar ‘Nature-based’ label. A Rome-centred perspective gave way to an evocation of the ‘learned schema’, but the Baetis was also the heart of the province’s human landscape. The tension between macro-geographical marker and local social reality is also visible in Rome’s first colonia outside Italy, Narbo, which derived its name from a river (the Narbon can only be the Aude, though it was later called Atax). And this river was the boundary used in the tradition preserved by Polybius to mark the other end of the important part of Europe (the Don was the far-remote eastern antitype). He went on to say that the Romans had by his time measured and marked with milestones the section from the Narbon to the Rhone.28 So the learned tradition was indeed cross-fertilised by commercial utility. But that should hardly surprise given the early history of Greek hydronyms in the world of overseas settlements.

• 29 ILS 2288, two dedications of the late second century AD from Rome commemorating all the legions of (...)
• 30 On the Via Claudia Augusta and rivers, Purcell, 1990a.
• 31 ILS 8995 diis patriis et Nilo adiutori/ Niloi sunleptori (sylleptor is an accomplice or assistant, (...)
• 32 Some striking modern parallels in Pick, 2005 and Blackbourn, 2006.
• 33 Purcell, 1990a for the display of labour in canalization. For the Antiochene canals, Pausanias 8, 2 (...)

21But that other provinciae than Baetica were also thought of as riverine is suggested by the early imperial usage of the labels superior and inferior, Germania, Pannonia and Moesia, where Rhine and Danube supplied the gradient which underlay the terminology.29 The role of communications is likely to matter to these cases where a navigable central river shapes the concept of a provincia. Roman planning linked rivers and roads. Where the great roads abutted on great rivers was always significant - both crossing and reaching counted.30 For Strabo (7, 3, 13), one of the only notable things about the Danube (fitting his preoccupation with hegemonikai chreai), was that it had recently served as the corridor for Roman military supplies. Cornelius Gallus rather patronisingly thanked the God of the Nile for being his ‘aide’ in his grandiose war in Upper Egypt.31 Canal-building and road-engineering were similar tasks for the general to plan and his army to execute. It is obvious that there is a close tie-up between the excitement of the geographical and historical idea of the river and the enthusiasm with which competitive commanders undertook to leave their mark on it.32 Marius on the Rhône, Augustus on the Nile, Drusus at the mouths of the Rhine and the Scheldt, the Flavian emperors on the Orontes, Trajan at the Iron Gates or the Isthmus of Suez are high-profile instances, but this is not the place for an extended account.33 Changing the order of the world was undoubtedly one of the resonant challenges in such undertakings, but the excuse was always to improve communications. And if communications were first for Roman rulers and their agents, they could hardly exclude a wide range of uses by Rome’s subjects, whose passage patterned the identity of the new routes.

• 34 Tolls on the Fossae Marianae: Strabo 4, 18; Plutarch, Marius 15, 4. The co-evolution of improvement (...)
• 35 See Gil, Torallas Tovar, 2010.

22The cosmological grandiloquence of river-thinking is apt to distract from such more utilitarian considerations. Interventions of this kind made the river more navigable by improving the physical features of banks and channels, and they made possible a regime of supervision and surveillance which could include the imposition of lucrative tolls.34 The place of a riparian tax in the imaginaire which shapes the strange late evocation of Hadrianic Cologne in the recently published Barcelona papyrus shows that such aspects mattered.35 The conscious management of riverine communications to foster economic life no longer seems such an alien idea. Revenue and its protection, materials and their supply, and the presence of representatives of the Roman res publica, especially under arms, made a widely comprehensible nexus. And this went well beyond the needs of communications.

• 36 Flood control on the Tiber is a partial exception, with Aldrete, 2007.
• 37 General reflections in Burchi, 2004; for a colonial context, Worster, 1985.
• 38 Beltran Lloris, 2006. Note the admirable breadth of the work of Hoffmann, 1996 (involving hydraulic (...)

24It is also odd that historians should be so unwilling to learn from and retroject the pressing contemporary political preoccupations of water-management.36 In most contexts in Antiquity water was indeed overall hugely more abundant per caput than it is in the Mediterranean and west Asia today.37 Overall : but that does not deny control of water an important political rôle at the margins of bad years and semi-arid regions. Flood-control and irrigation as a display of power, for instance, suggest that planners might develop catchment-area-wide conceptions of the river : the lex rivi Hiberensis, concerning, as it does, the management of the waters of one of the largest marker-rivers of Hellenistic geography, a notable constituent of the diplomatic topography of the third century B.C., is a persuasive indication.38

• 39 For the term ‘hydraulic landscape’, coined for the irrigation-zones of Muslim southern Iberia, Glic (...)
• 40 For the term, Purcell, 1996.

25Beyond the fact of control of great rivers, Roman power was embedded in the whole hydraulic landscape, in a way that could seem miraculous.39 When Titus’ army approached Jerusalem, Siloam and other springs that had long been nearly dry all began to flow in the greatest abundance (Josephus, BJ 5, 410). Rome had striven to display its mastery of the ‘uncontrolled periphery’ of environmental water since its early cultural history.40 But that entailed a different set of discursive relations from the imposition of a master-plan of scientific geography.

• 41 Drinkwater, 1975.
• 42 The Periocha of Livy 139 strongly suggests that at Lugdunum before A.D. 14 Gaul venerated its conqu (...)

26The broadly Augustan age apparently offers a further conspicuous exhibit of the ‘learned schema’ of river-thinking : the colonia at Lugdunum, founded on Caesar’s plan by Munatius Plancus in 44 on the hill of Fourvière, directly above the confluence of the Rhône and Saône.41 The first Roman citizen-settlement in Gallia Comata is thus set at the junction of the most famous river of the region, the Eridanos - another Eridanos - famous since the age of Greek settlement, with its most important and impressive tributary. The statement is clearly made in the language of Hellenic planetary geography, and uses that new idiom to express a centrality which is an artefact and an instrument of imperial domination. The well-attested Roman appropriation of these themes might also be seen to feed into the choice. The Rhône is the Tiber of the new colonia, the Pô of the new Gallia. The site is not coincidental, since the actual confluence in the plain beneath was celebrated by being made the location for the Sanctuary of loyalty to Rome which became that of Roma and Augustus.42 The Romans made their own characteristic addition to the order of Nature, extending the rivers with the road network, which duly included a Gallic thauma in the shape of the road built by Agrippa from Lugdunum northward to the river of Ocean (Strabo 4, 6, 11). The topography of the rivers was made to express the novel hegemony over Gaul of the senior alien city and Roman capital. The sanctuary’s festival, and the amphitheatre built for it in the reign of Tiberius, are emphatically Roman ; but the we must recognise that others are present too : the annual presence, and the religious participation, of the representatives of the civitates of Gaul at the festival of the Confluence are essential too.

• 43 For the document, Sánchez-Ostiz, 1999; on the tumulus, Panter, 2007.

27That these foundation acts at Lugdunum were doctrinaire is spectacularly confirmed by what we now know of the intended centre of Roman Germania, Moguntiacum. The site is on the central course of the great river which is the conceptual key to understanding Germany’s geography, the Rhine, just at its confluence with a major right-bank tributary, the Main. Here the Roman community was the hiberna of the legions of Germany, but outside the perimeter of the Roman base, on a hill precisely opposite the confluence, was a theatre, and the honorarius tumulus of Drusus, the pacifier of the area, around which the peoples of Germany were summoned to conduct their annual ritual of homage to Roman power : all this documented by the Tabula Siarensis.43 As at Lugdunum, the set of messages seems imposed, external and thoroughly hegemonial, and it appears that the same blueprint was that which shaped the colonia at Corduba on its great river and highway to the edge of Ocean as the capital of the Augustan province.

• 44 See Bedon, Malissard, 2001.
• 45 They too have west Asian parallels, however: see Harmansah, 2007.
• 46 I took too top-down an approach in Purcell, 1996. See Coles (1994) for interesting thoughts on the (...)

28There are reasons, though, for thinking the position more complex. How effective, we might further ask, is the west Asian and Greek concept of world-rivers as a way of intuiting the new organisms of Roman provincial power ? The Lugdunum sanctuary was named Condate, the Gallic word for confluence. There is, perhaps surprisingly, no sign that confluences mattered in Roman (as, for instance, in Hindu) religious thought. But they did to the Gauls. Is the appeal of the rivers not rather that they meant something not to the Roman educated élite but to the peoples of the three provinces ? Strabo implies something of that sort in his famous praise of the river-system of Gaul, a passage which certainly looks backward to before the conquest (4, 1, 2).44 The notion of a river, as we have already seen, is useful on the ground for patterning the geography of whole regions only if you have a reasonably precise idea of which of its headwaters to choose as its own origin. Headwater sanctuaries - of which the most famous is that of the sources of the Seine - are, again, more a feature of Gallic than of Roman thinking.45 That applies to provincia Britannia too, where Romans likewise appropriated a fluvial topography to their own purposes, but one which had a vigorous local life of its own.46 Should we likewise see a response to indigenous sensibilities in the recognition of the springs of the Baetis (above) ? No terra incognita indeed, then, a Roman province was shaped dialectically with the concepts and mentalities of Rome’s subjects. Local knowledge laid out parts of the Roman hegemonial map.

• 47 Adelman, Aron (1999, 2005) offer an instructive contrast from colonial North America.
• 48 Schadee, 2008.

29Where, however, did provincial input into the conceptual administrative-geographic system come from ? Rivers and their confluences, to begin with, were often precisely the locations of diplomatic negotiation, neutral space between debatable terrains. Their geography was thus one of real diplomatic encounter, as well as an artefact of the ‘imperialism of categories’.47 But they were also the arteries and ganglions of the inter-regional negotiation of the trader, which replicated ‘diplomatic’ negotiation at a humbler social level. Markets took place beside rivers and on river-islands as well as diplomacy. Commercial go-betweens had shaped the early Roman experience of the Provincia. Caesar had based his nascent understandings of Gallic geography above all on the opinions and reports of traders, which underpinned the complex appropriations by which he invented the spatiality of a new segment of the Roman empire.48

• 49 Duval, 1956; Lavagne, 1985.
• 50 There has been excellent work in this area in relation to northern Gaul and the lower Rhine: Verger (...)
• 51 Adams, 2003 (on the moritex); Stuart, Bogaers, 2001 (for Nehalennia).
• 52 Something similar might be argued about the geography of watery healing cults and its relationship (...)

30Alongside the festival of Condate, then, we should be prepared to set the spectacular Tiberian monument of the nautae Parisiaci - the Seine boatmen, who chose to stress both their civitas and their combination of Roman and Gallic religious affiliations, in a dedication of hybrid artistic register, set up in close association with the Seine, and probably on the Ile de la Cité itself.49 In this monument the users of the river par excellence are found forging new imperial and provincial identities for themselves, their civitas, their river, their social milieu, and their business. These are the people who inhabited the hydraulic landscapes, who made them useful to rulers and ruled alike. And as at Condate, the register for the new expressions is religious, and it was through the creation and dissemination of religious messages that all levels of society, including Romans and Gauls, expressed interactions which were strongly geographical in flavour.50 Similar expressions in relation to the rivers which fed both sides of the Narrow Seas developed under the empire among the mercantile coteries who dedicated to Nehalennia at Colijnsplaat. The new dedication from London of a moritix Londiniensium, a Bellovacian by origin, belongs in a similar context : and this honoured Mars Camulus, Roman god and god of the first colonia of the province of Britain.51 The reception of political and administrative geography in this milieu is certain - why not attribute to them an important contribution to the thought-world of the fluvial geography of power ?52

• 54 Wallace-Hadrill (2005, p. 81) thus seems wrong to conclude: ‘it is not that the rationalist instrum (...)

33The Augustan geography of power represented an evolution rather than a revolution. Its workings depended on an asymmetric reciprocity between Romans and provincials.54 Rather than a regime devising new intellectual instruments of maintaining order, we should prefer to speak of change brought about in thousands of local contexts by various responses to a quite limited set of rather traditional initiatives by the rulers of the empire, innovative only in the scale and consistency with which they were administered. And that seems to me to be clearly illustrated by the intricate role in the construction of imperial space played by the rivers of the western provinces.