During the Roman republic, the river Rubicon marked the boundary between the Roman province of Cisalpine Gaul to the north-east and Italy proper to the south. The river distinguished not only the geographic boundaries for the province but also the military restrictions for governors and magistrates. Therefore, rulers required generals to disband their armies before entering Italy, and if a general entered Italy while exercising command of an army, both the general and his soldiers became outlaws who automatically faced death.