Short answers, pulled from the story.
Drusus founded the Sanctuary of the Three Gauls in 12 BC as a rapid response to a rebellion provoked by the census of Gallia Comata. This site became the earliest and most important institution of its kind in the Western Roman empire.
Caius Julius Vercondaridubnus emerged as the first high priest from the Aeduan elite during the inauguration on August 1st of either 10 BC or 12 BC. His name indicates both Roman citizenship and Gallic origins while his office required Roman citizenship but early councils combined citizens and non-citizens.
The geographer Strabo described the sanctuary located on the hillside of la Croix-Russe at the junction of rivers before the city proper. The monumental altar and its 50-meter base were constructed from marble with two winged victories of gilt bronze flanking the structure holding palms and gold crowns.
Lugdunum hosted a major Imperial mint whose coinage provides principal evidence for altar form and development including silver and gold coins produced there according to Strabo's geographical description. Coins issued under Augustus depict the altar of the Three Gauls with specific iconography such as winged victories holding palms and gold crowns standing on Ionic capitals.
A draper discovered a bronze plaque in his vineyard during 1528 on the sanctuary site that measured 2.5 meters by 1.93 meters and bore Claudius's speech from 48 AD. This inscription made Gallic chieftains eligible for Roman magistracies and Senate membership while the tablet now resides within the Gallo-Roman Museum of Lyon after its unearthing.
Septimius Severus re-founded and reformed the Imperial cult center shortly after 198 or 199 AD following defeat of Clodius Albinus transforming the sanctuary into an instrument of suppression and autocracy. The image of dea Roma was removed from the ara and confined to the temple interior while images of living and deceased Augusti combined uniquely within Western Empire religious practice.