While Brutus did not give exact reasons for murdering Caesar, he and the 40 senators that killed the dictator did so collectively because they felt Caesar was a threat to their own positions in the Senate. Caesar not only appeared on the denarius coin but was named by some senators as dictator in perpetuity. The motive for the killing then was sparked by Caesar's supposed claims of kingship.
Brutus started to conspire against Caesar after he referred to himself, as well as his co-conspirator, as Liberators. He and his fellow murderers believed Caesar wanted total control and dictatorial authority over the Roman Empire. His continuing power posed a threat to the influence these men exerted and therefore resulted in a coup.
When friends in the Senate made Caesar a dictator, his fate was sealed. He was also named Father of his Country. The ruler proved to be instrumental in the reformation of Rome. Although Caesar served only a year before his death, he transformed the Roman Empire by increasing the size of the Senate and reorganizing the local government.
While Caesar's governmental reforms were approved by the citizenry, his efforts did have the same effect on certain members of the Senate. Many of the men envied Caesar's power and believed that the ruler was an aspiring monarch.