Why did Roman Republic ended when who came to power?

The Roman Republic ended primarily due to the rise of Julius Caesar, who became increasingly powerful and popular. His crossing of the Rubicon River in 49 BCE ignited a civil war, leading to his appointment as dictator for life in 44 BCE. This concentration of power sparked fears of tyranny and ultimately resulted in his assassination, but the subsequent power struggles paved the way for the establishment of the Roman Empire under his adopted heir, Octavian (Augustus).