The Roman Empire was a huge ancient empire that ruled most of Europe, the Middle East and North Africa from 27 BC to 476 AD. It was started by a powerful ruler called Julius Caesar and it grew to be the largest empire ever seen up until that time. The Roman Empire was known for its great public works, such as roads, vast public buildings, and a strong military. It brought a lot of cultures and art together, and was a major part of the development of western civilization.