Abstract The Tabula Lugdunensis, unearthed at Lyon in 1528, preserves part of a speech that emperor Claudius delivered to the Senate in 48 CE, to argue in favour of admitting the elites of north-western Gaul to the Roman senate. This article presents a rhetorical analysis of the speech. Modern readers have labelled the style of the speech ‘bombastic’ and ‘pedantic’, while criticising its many historical examples. An examination of the speech in terms of inventio, dispositio and elocutio, however, demonstrates that Claudius carefully constructs the ethos of an erudite and open-minded authority. Two moments of rhetorical persuasion can be distinguished: first, the Senate meeting in Rome itself and, second, the publication of the bronze inscription at the Sanctuary of the Three Gauls at Lugdunum. Not much deliberative rhetoric was perhaps needed to persuade the senators to agree with their emperor; the display of the inscription, on the other hand, could be interpreted as a form of epideictic rhetoric, which may have given a significant boost to the self-confidence of Roman citizens in Gaul. While some senators in Rome may have disliked the lengthy historical exempla in the oral speech, visitors to the sanctuary in Lugdunum may have appreciated seeing Gaul included in the long history of Rome.