The notable Roman general who fought against Pompey during the civil war was Julius Caesar. Their conflict was part of a broader political struggle that emerged from the power dynamics within the late Roman Republic. Initially, part of the First Triumvirate along with Pompey and Crassus, relations soured after Crassus' death and political rivalries intensified. When the Senate favored Pompey, Caesar crossed the Rubicon River in 49 BCE, defying Senate orders and igniting civil war. This civil war ultimately led to Caesar's victory, his rise to power, and the eventual transformation of the Roman Republic into the Roman Empire.