Definition
The Roman Republic was the system of government Rome adopted around 509 BCE after expelling its last king, and which lasted until the rise of the emperors in the late first century BCE. Its guiding principle was that no single person should hold unchecked power.
Authority was instead spread across elected magistrates, popular assemblies, and a senate of experienced statesmen. The Republic governed Rome through centuries of dramatic expansion, turning a regional power into the master of the Mediterranean.
Why it matters
How it works
The Republic balanced power by separating it. Different functions — commanding armies, judging cases, managing money, proposing laws — were assigned to different offices, and most offices were collegial, meaning two or more people held them at once and could block each other. Term limits ensured power changed hands regularly.
This balance worked while Rome was modest in size, but conquest brought wealth, professional armies loyal to generals rather than the state, and bitter class conflict. By the first century BCE, ambitious commanders such as Julius Caesar overwhelmed the old checks, and the Republic gave way to one-man rule.