The Byzantium & Gaul Pack Add-on for Sid Meier’s Civilization VI has 7 achievements.
In Dramatic Ages Mode, enter a Golden Age with an excess 20 Era Score
Win a regular game as Basil II.
Win a regular game as Ambiorix.
As Byzantium, take the original capital of Rome while it is following your founded religion.
As Gaul, kill a Tank with a Gaesatae.
In Dramatic Ages Mode, lose 4 or more cities by entering a Dark Age.
In Dramatic Age Mode, as Georgia, have simultaneously a Golden and a Dark Policy active.