When Caesar crossed the Rubicon, the boundary of "Italia", beyond which troops would never cross, to defend the Republic from those who hated his "populism". He brought with him one legion. The 13th. They secured Rome from the Senate who refused to acknowledge his claim of consul. They secured the treasury, and held the city while Caesar consolidated his few loyal senators.

When Caesar crossed the Rubicon, the boundary of "Italia" beyond which troops would never cross to defend the Republic from those who hated his "populism". he brought with him one legion. The 13th. They secured Rome from the Senate who refused to acknowledge his claim of consul. They secured the treasury, and held the city while Caesar consolidated his few loyal senators.