An empire is an aggregate of many separate states or territories under a supreme ruler or oligarchy. This is in contrast to a federation, which is an extensive state voluntarily … 展开

Bronze and Iron Age empires
Stephen Howe writes that with the exception of the Roman, Chinese and "perhaps ancient Egyptian states", early empires seldom survived … 展开

United States of America
Contemporaneously, the concept of empire is politically valid, yet is not always used in the traditional … 展开

Empire versus nation state
Empires have been the dominant international organization in world history:
The fact that tribes, peoples, and nations have made empires points to a fundamental political dynamic, one that helps explain why … 展开

Empires originated as different types of states, although they commonly began as powerful monarchies. Ideas about empires have changed over time, … 展开

Roman Empire
The fall of the western half of the Roman Empire is seen as one of the most pivotal points in all of human … 展开

The chart below shows a timeline of polities that have been called empires. Dynastic changes are marked with a white line.
• The 展开