>...According to Suetonius, Caesar's assassination ultimately occurred primarily due to concerns that he wished to crown himself the king of Rome.[13] These concerns were exacerbated by the "three last straws" of 45 and 44 BC. In just a few months, Caesar had disrespected the Senate, removed People's Tribunes, and toyed with monarchy. By February, the conspiracy that caused his assassination was being born.

https://en.wikipedia.org/wiki/Assassination_of_Julius_Caesar