Final answer:
Caesar Augustus's rise to power marked the end of the Roman Republic and the form of government that disappeared from Rome was the Republic, being replaced by a monarchy under Augustus's rule.
Step-by-step explanation:
When Caesar Augustus came to power, the form of government that disappeared from Rome was the Republic. The Roman Republic was a system of government where elected officials, known as consuls, held power. However, Augustus transitioned Rome into a monarchy, establishing himself as the first Roman Emperor. This marked the end of the Roman Republic and the beginning of the Roman Empire.
Learn more about The transition from the Roman Republic to a monarchy under Caesar Augustus