First Mithridatic War
The First Mithridatic War (88–85 BC) began with a declaration of war by the Senate. The "casus belli" was the Asiatic Vespers, although some few claim that war was declared first; that is, that the Vespers were a reaction rather than a cause. Consul Lucius Cornelius Sulla having received the mandate by lot was given several legions fresh from the Social War to implement the mandate.