Italy has a long history stretching back nearly 3,000 years. Rome began as a small city but grew to become a vast empire that controlled much of Europe and the Mediterranean world. Rome had a powerful organized army and advanced military technologies that helped it conquer neighboring territories. Roman culture was heavily influenced by the Greeks and included social hierarchies and religious practices centered around adapted Greek gods. The Roman Empire collapsed in the 5th century AD but its contributions such as roads, aqueducts, and concrete remained influential. Italy later unified as a kingdom and is now a democratic republic.