Explanation: After the assassination of Caesar, the assassins found themselves in a precarious position. Having found that the Roman people were not, in fact, enthused about yet another Populare reformist politician being assassinated, dictator or not, they were forced to come to terms with Caesar's political partisans. In exchange for granting recognition of Caesar's extensive reforms, and the recently-held elections (during which many of the assassins had actually won office with the assistance of Caesar), they were offered amnesty for their killing.
It wasn't long before the Second Triumvirate, an alliance of three of Caesar's supporters, decided to revoke that amnesty, and condemned the assassins to death instead.
The Second Triumvirate went on to divide Rome between themselves, and then, eventually, squabble with each other over ultimate power, with the winner, Octavian, later known as Augustus, emerging as the ultimate autocrat of the Roman Empire.
Oh, sorry, the armed men in the back are gesturing that I misspoke. I mean Octavian emerged as 'just the first citizen' of the totally unchanged Roman Republic (which we would come to know as the Roman Empire).