sep 14, 509 BC - Rome becomes a republic
This is significant as the republic was similar to a democratic government. This affected the Roman Empire as it influenced the senate witch allowed for many conqurered nations or states to be represented. This made lots of citezins and conquered states happy whic decreasaed the chance of a rebellion forming inside of the empire. Also, the fact that the conquered states would be represented in the sentae made the prospect of joining the empire appealing. This increased the expansion of the empire which led to its growth.
Added to timeline:
Events that Led to the Growth and Fall of the Roman Empire