The shift from the Roman Republic to the Roman Empire began in the late 1st century BCE and early 1st century CE. The Roman Republic was facing significant challenges, including political instability, economic problems, and social unrest. As a result, prominent military leaders emerged, such as Julius Caesar, who were able to gain a significant amount of power and influence over the Republic's government. After a series of civil wars, Julius Caesar became the sole ruler of Rome, but his assassination led to another power struggle. Eventually, his adopted son Octavian emerged as the most powerful figure in Rome, and he established a new form of government known as the Principate. This new government system marked the beginning of the Roman Empire,