Asterix Versus Caesar (1985)

Asterix Versus Caesar (Astérix et la surprise de César) is the first of the 1980s Asterix films and the fourth film adaption based on the Asterix comic books. It was released in 1985. The plot was adapted primarily from the books Asterix the Legionary and Asterix the Gladiator by Goscinny and Uderzo's friend Pierre Tchernia.

More at Wikipedia.