What person is generally thought of as being most responsible for Rome's move from a republic to a dictatorship?

Julius Caesar is generally considered the key figure responsible for Rome's transition from a republic to a Dictatorship. His accumulation of power, military conquests, and appointment as dictator for life in 44 BCE undermined the republican system. Caesar's actions, including bypassing traditional senatorial authority and centralizing power, ultimately led to his assassination and the subsequent rise of the Roman Empire under his adopted heir, Octavian (Augustus).