This period is characterized by an age of empires. From northern Mesopotamia, the Assyrians renew their military campaigns over an ever-wider region. Their armies defeat cities as far west as the Mediterranean Sea and Egypt and carry back to Assyria vast quantities of booty and tribute. By installing Assyrian governors in conquered capitals, and through the mass deportation of defeated populations, they create a unified empire. The Assyrian empire falls in 612 B.C. to the combined forces of the Babylonians and the Iranian Medes. The Babylonians dominate Mesopotamia until 539 B.C., when Cyrus the Great of Persia, who has already overthrown the Medes, incorporates it into his rapidly growing empire. Under his Achaemenid successors, the Persian empire stretches from India and Central Asia to Egypt and Greece. After more than 200 years, the Persian empire is seized in 331 B.C. by Alexander of Macedon. Following Alexander’s death, his generals divide the empire, with the region from Syria to India falling to Seleucus. By the end of the first century B.C., the Seleucid empire ceases to exist: Mesopotamia is in the hands of the Iranian Parthian empire while northern Syria faces the advance of the Romans.