In 12 BCE, Drusus, the stepson of Augustus, founded the cult centre of the Tres Galliae at Lugdunum (Lyon), at the confluence of the Rhône and Saône rivers, just below the hill on which a Roman colony had been established one generation before (Woolf, Becoming Roman,p. 216; for discussion regarding its exact location, including synthesis of previous arguments see Frascone, Une nouvelle hypothèse, p. 189-216). Following Julius Caesar’s Gallic Wars, Augustus had sought to reorganise the region into the three imperial provinces of Gallia Aquitania, Gallia Belgica and Gallia Lugdunensis, with Lugdunum established as the centralised and permanent strategic base for the imperial governors of each province. The foundation of the sanctuary, and its monumental altar, is attested in a number of ancient sources, which make it clear that the sanctuary had come into being following the trouble that had broken out over the taking of the census in Gaul. Livy and Cassius Dio report that this trouble had disturbed the rear guard of Drusus’s forces, which were currently engaged in a difficult campaign in the Rhineland, against the tribe of the Sugambri (Dio, Roman History, LIV.32; Livy, Periochae, CXXXIX. See Deininger, Provinziallandtage, p. 21ff). According to Cassius Dio, in order to avoid further unrest, Drusus summoned the leading men from the three imperial provinces to Lugdunum to celebrate a festival associated with an ‘altar of Augustus’ (Roman History, LIV.32.1), thereby giving him the opportunity to meet with representatives of the ‘Three Gauls’ and to resolve their disputes. The details in Dio and Livy provide a date of 12 BCE for the dedication of the altar, but Suetonius’s version attributes it to the year of the emperor Claudius’s birth, in 10 BCE, leading to suggestions that the altar was inaugurated in 12 BCE, and then formally dedicated two years later when Augustus himself was known to have been present in the region (see Turcan, “L’autel de Rome et d’Auguste,” p. 608). Duncan Fishwick has largely dismissed this suggestion, preferring to understand Suetonius’s reference to Claudius’s birth as occurring on the anniversary of the dedication; as the dedication of the altar was a major local event in the provinces of the Three Gauls it reasons that Suetonius would use it to stress the coincidence of Claudius being born on the anniversary of its dedication, which also fits with Claudius’s re-issue of coinage that depicted the altar on his fiftieth birthday, in 41 CE (Fishwick, Imperial Cult, p. 98-9). In any case, it is clear that the dedication of the altar and the construction of a monumental sanctuary area was a significant event; it was the first of its kind in the Latin West, dedicated to the imperial cult and organised along wholly Roman lines at a time when Roman power was stretching further into Gallic territories (Woolf, Becoming Roman, p. 216).

The construction of the altar may not, however, have been directed purely by Roman initiative. Although he is uncertain of the scholarship that suggests a pre-Roman celebration of a Celtic god named ‘Lug’ on the site, Duncan Fishwick has noted that Drusus’s summoning of the principal men of the three Gauls was based on Gallic precedent, which saw tribal gatherings as a means of debating ‘intertribal’ concerns (Fishwick, Imperial Cult, p. 100; for arguments contra the festival of ‘Lug’, see p. 99-100, with notes). Julius Caesar himself had met with the Gallic leaders on a number of occasions, with the area apparently maintaining some autonomous organisation that made it an ideal federal meeting spot for convening the three provinces (Larsen, Representative Government, p. 146; Fishwick, Imperial Cult, p. 101).

Little survives of the altar today, with just five finds confirmed as having come from the sanctuary site. The only monumental architecture to have been identified is a 15m long section of wall, discovered in 1990 at the south-east corner of the Montée de la Grand Côte and the rue Burdeau (Frascone, Une Nouvelle Hypothèse, p. 191). The size of this section of wall has been interpreted as being part of the paved ramp that led up to the sanctuary on a north-south axis (Frascone, Une Nouvelle Hypothèse, p. 191). Other discoveries include a fragment of a gold crown that may have adorned a statue of a winged Victory at the site, a bronze leg of a horse that may have come from an equestrian statue, some marble plaques, a fragment of monumental inscription and the noted ‘Lyon Tablets’, which record part of a speech of Claudius to the Senate (for more precise details regarding these finds, please see Tranoy & Ayala, ‘Les pentes de la Croix-Rousse’, p. 171-189; Chomer & Le Mer, Lyon).

However, in spite of the minimal number of finds from the site, it has been possible to reconstruct the altar from literary descriptions and its depiction on coinage. The main literary source is a description in Strabo, who describes it as being ‘remarkable’, and inscribed in some place with the names of the sixty tribes who made up the provinces of the Tres Galliae. He also describes sixty statues, one representing each tribe, which stood nearby (Strabo, Geography IV.3.2). The coin images reveal more about the altar and its decoration; the imperial mint at Lugdunum struck a number of aeres – altar coins – between the reigns of Augustus and Nero, the reverses of which depict (with minor variations), a broad rectangular altar decorated with imperial insignia, flanked on each side by large columns with winged Victories placed on top, carrying wreathes and palms. Below the altar is an inscription, which appears to dedicate it to Rome and Augustus (for these coins, see Fishwick, Imperial Cult, p. 104, n. 50). A series of marble pieces excavated in 1859, decorated with a fine relief of an oak swag and two axes and dated according to the iconography to the Augustan period, may also have come from the altar and decorated its shorter sides or back (Turcan, “L’autel de Rome et d’Auguste,” p. 615; for the location of these pieces in a different part of the sanctuary, see Audin, Essai, p. 154). There has been much debate regarding the meaning of the imagery on these coin types and in the recovered fragments; some, such as Harold Mattingly, have found the imagery too ambiguous to draw meaning from (Mattingly, Coins, p. I, 92). Others, such as Andreas Alföldy, have interpreted the combination of wreathes and palms as oak wreathes and laurels, emphasising the connection between these and the corona civica (civic crown) symbolic of Augustus’s reign (Alföldy, Der Vater des Vaterlandes). Parallels can also be drawn between the coin imagery and the surviving evidence from the Ara Pacis, which was also decorated with similar themes. Indeed, as Duncan Fishwick has stated, there can be little doubt that, on the basis of the coin evidence, the altar in Lugdunum bore “a group of symbols that collectively incorporate the major elements of Augustan ideology” (Imperial Cult, I, p. 107; for further discussion of these elements, see p. 107-125).

Although the altar at Lugdunum was part of the first imperial cult centres to be established in the Latin West, it was far from being the last; similar sanctuaries were set up in Gallia Narbonensis, across Spain, and even in Britain. What was unique about the altar complex in Lugdunum, however, was the enthusiasm with which it was received by the local elites of the new Gallic provinces. Although the initial organisation came from Rome, through Drusus’s request, the cult was eagerly embraced; it was established as the venue for an annual assembly for representatives of the three Gallic provinces, at which the imperial cult would be honoured, along with elections for offices of the cult, annual priesthoods and a membership of a local council (Woolf, Becoming Roman, p. 216-7). Candidates for these positions were drawn from the most prominent civic decurions, and priesthoods of the altar came to be recognised as the most prestigious and esteemed positions in Gallic administration, not least because of its pre-requisite of Roman citizenship; as Greg Woolf has said, at the altar of the Tres Galliae and the associated cult practices, the ‘noblest Gauls had the opportunity to compete for prestige on a wider stage than any civitas could offer’ (Becoming Roman, p. 217; for the priests of the altar, see Deininger, Provinziallandtage, p. 99-107). There is little sign that this cultic administration was interpreted as a sign of Roman oppression, with the Gallic nobility engaging fiercely in euergetistic displays to emphasise their status and competing for popular support in a way quite unprecedented in the region. This euergetism included the construction of an amphitheatre next to the altar complex during Tiberius’ reign, and the giving of lavish gladiatorial games by successfully elected priests (for the amphitheatre, see Maurin, Saintes Antiques, p. 181-2). The cost of the games increased so dramatically that the Senate in Rome was forced to issue a decree limiting the amount spent to prevent the priesthood form becoming exorbitantly expensive (Oliver and Palmer, Minutes, p. 320-49). The problem of extravagance at the games is better understood, however, as a sign of the success of the cult, rather than any kind of failure; the local population and their leaders were actively engaged and participating in a new form of civic and religious behaviour that had, at its origin, the foundation of the cult (Woolf, Becoming Roman, p. 217-8). The sanctuary at Tres Galliae represented the integration of the principate’s military, civil and religious policy in a previously unstable province; it created a focus of loyalty to the emperor and a new avenue for the native aristocracy to express their ambitions and compete for privilege.