In 1859, fragments of an inscribed marble plaque were excavated from the site of the altar of Tres Galliae, with traces of the inset for two letters – RO – still evident. The height of the inscribed letters – 0.38m – corresponded to the size of monumental lettering designed to hold bronze inlays, and the length of the total inscription (should the restoration be correct) would have reached perhaps 8m in length, suggesting it was originally a text of some significance (Fishwick, Imperial Cult, p. 105). The restoration of the inscription has been proposed as Romae et Augusto – “(dedicated) to Rome and Augustus,” based on coin images from Lugdunum which depict the altar with this inscription. Although some scholarship has questioned whether or not this fragment was actually from the altar itself, it would seem reasonable to connect the fragment with the well-known legend of the coinage (for the contrary argument, see Audin, Essai, p. 154, with full discussion in Fishwick, Imperial Cult, p. 308-16).

The ‘altar’ coins that depict the image of the altar with the inscription beneath it were struck at the imperial mint of Lugdunum between 12 BCE and the reign of Nero, in the second half of the first century CE. In these coin images, the inscription is found above the altar, beneath a series of unidentified objects that hang over it, making it almost impossible therefore to locate the exact position of the text on the monument itself. The suggestion of a ledge immediately beneath the altar, on which the inscription was placed, has been dismissed owing to a lack of archaeological evidence or similar examples; the front face of the altar has also been dismissed, due to a lack of space amongst the relief decoration. A possible location may be above the inscribed names of the sixty tribes mentioned by Strabo, but this is again conjecture (Fishwick, Imperial Cult, p. 125-6). Irrespective of the actual location of the inscription, however, the fragment is important because it confirms the dedication made by the coin images, that the altar was dedicated to the goddess Roma and the emperor Augustus, most crucially at a time when he was still living.

The precedent for a cult of the living emperor came from the East, where cults to the Hellenistic Kings had been well established. In the Roman Republic, similar cults had been set up for Roman military generals there too, but it was a decision taken by Octavian in 30/29 BCE that established an organised model for emperor worship. A cult was instituted, with his permission, in Ephesus and Nicaea to worship Roma and Divus Iulius, and the Roman citizens resident there were instructed to participate alongside the provincial audience (Cassius Dio, Roman History, LI.20). It would appear that the provincial audience was not satisfied with this grant of worship however, as both Cassius Dio and Tacitus record instances of proposals made by eastern koinē (councils), such as from Asia and Bithynia, who wished to institute the worship of Augustus alongside the cult already granted to them (Cassius Dio, Roman History, L1.20; Tacitus, Annals, IV.37). This was perhaps unsurprising given his victory at Actium and the region’s previous habit of honouring military generals with a form of ‘ruler’ cult following important victories (see Bowerstock, Augustus and the Greek World, p. 112-116; Fishwick, Imperial Cult, p. 32-45). However, for Augustus, the establishment of a personal ‘ruler’ cult – and the associated pretensions of divinity – was more problematic, and could lead to unfavourable comparisons with Julius Caesar and Marc Antony; his solution was to permit an honour that satisfied the demands of the provincial request, but which still retained an air of political acceptability, by permitting cult worship in his name only if the goddess Roma was added to the ritual activity.

Roma was not an unknown goddess in the Greek east; Dea Roma had been worshipped there for some time, and a priesthood had been awarded in the name of Roma and the proconsul of Asia, Publius Servilius Isauricus, in 46 BCE, establishing a precedent for Augustus’s actions (Fishwick, Imperial Cult, p. 50, n. 28). Dea Roma was not, however, well known in Rome; following Augustus’s victory at the Battle of Actium her cult took on a new significance, becoming the embodiment of the new imperial system and its capital city. As Ulrich Knoche has demonstrated, her combination with Augustus became a symbolic union, epitomising the res Romana (Die augusteische Ausprägung der dea Roma, p. 324-49). Although Augustus was careful not to advertise her prominent status in the cults of the city of Rome – she was not included as an official state deity until the reign of Hadrian (see Weinstock, Treueid, p. 312) – Roma nonetheless took on a significant role in imperial ideology and became a characteristic motif of the Augustan regime. The word order of the alliance between Augustus and Roma was carefully precise, Roma came first and was therefore clearly most important in terms of precedence yes, this is important to recall; Augustus was able to share in the honours awarded to her as a deity, without laying claim to the same divine status himself (Fishwick, Imperial Cult, p. 129).

The fragment of inscription from the altar at Lugdunum clearly indicates that Roma and Augustus were worshipped in the same way in the Latin West, albeit with less popularity than they enjoyed in the Greek east. The strict adherence to the formula established by Augustus for the cult in the East is evidenced by the inscription, the coins, and the epigraphic record of the provincial priests, which record the activity of the cult and the particular priesthoods associated with it. At the altar at Ludgunum, Roma and Augustus were worshipped as equals, celebrating the same rites, ceremonies and honours; Augustus, although still clearly a living man, was celebrated with the same behaviour reserved for the gods, which put him – as Duncan Fishwick states – on the same cultic level as the goddess, whom he had ‘transformed into a symbol of imperial Rome’ in the West (Imperial Cult, p. 131).