An empire is a set of lands or regions that are ruled by an emperor. Usually, the emperor has governors, viceroys or client kings who each rule one land or region. An empire usually also has many different cultures.
Well-known empires include the Persian Empire, the Roman Empire, the Russian Empire, the Ottoman Empire, and the British Empire. The first person to create an empire was King Sargon of Akkad, who legend says was destined to rule, established the world's first empire more than 4,000 years ago in Mesopotamia. The Akkadian Empire was the oldest empire in the world.
Many empires grew mostly by conquering land neighbors and are called land empires. Sea empires grew mostly by sailing to distant places and conquering them. The Aztec Empire and the Mongol Empire were land empires. The Venetian Empire and the British Empire were sea empires.