Political Rivalry: Caesar's rise to prominence and power threatened the interests and authority of other influential Roman politicians and senators. His political opponents, including members of the Senate, saw him as a potential dictator and a threat to the traditional balance of power in the Roman Republic.
Populares vs. Optimates: Roman politics was divided between the Populares (populists) and the Optimates (conservatives). Caesar belonged to the Populares faction, which sought to represent the interests of the common people and challenge the power of the aristocratic Optimates. His association with the Populares alienated many members of the Optimates, who saw him as a radical and a threat to their privileges.
Fear of Caesar's Ambition: As Caesar gained military victories and achieved great popularity, some Romans began to fear his personal ambition and quest for power. They worried that he might become a tyrannical ruler and undermine the Republican system.
The First Triumvirate: Caesar's involvement in the First Triumvirate with Pompey and Crassus raised concerns among those who believed that the alliance concentrated too much power in the hands of a few individuals, bypassing traditional political institutions.
Violation of Republican Norms: Caesar's actions, such as crossing the Rubicon River and marching on Rome with his army, were seen as violations of the Republican constitution. Many Romans believed in maintaining the separation of military and political power and felt that Caesar's actions threatened the delicate balance of the Roman Republic.
Personal Grudges: Some individuals had personal grievances or rivalries with Caesar, leading them to oppose him. For instance, Cato the Younger, a staunch defender of Republican principles, strongly opposed Caesar's rise and criticized his actions.
Cicero's Criticism: Marcus Tullius Cicero, a famous Roman orator and politician, was one of Caesar's vocal critics. Cicero feared Caesar's dictatorship and condemned his actions in speeches known as the Philippics.
These factors contributed to the opposition that Julius Caesar faced from certain groups and individuals within the Roman Republic.