As - Tiberius ROM ET AVG, altar of Gauls

Struck at Lugdunum (modern Lyon) under Augustus, this issue bears the altar of the Three Gauls — the famous sanctuary erected at the confluence of the Rhône and Saône in 12 BC by Drusus, Augustus's stepson, as a focal point for the imperial cult in the newly pacified provinces. The altar served as an annual gathering point for delegates from sixty Gallic tribes, making it as much a political instrument as a religious one.

The obverse attribution to Tiberius places this among coins struck just before his adoption as Augustus's heir in AD 4 formally consolidated his succession — minted, in other words, during the years when that outcome was still being negotiated.