320. On the death of Alexander the great his vast empire was almost immediately broken up into three main divisions. In the East, his General Seleucus Nikator founded an empire comprising Persia, Mesopotamia, Syria and part of Asia Minor, that is, almost all the area from the Hellespont to the Indus. The capital of this empire was Antioch, which became one of the greatest commercial centers of those times, through which merchandise for Arabia, India and China flowed into the Mediterranean.
The second division of the Alexandrian empire was the Graeco-Egyptian kingdom founded by Ptolemy I, another general of Alexander. Its chief city was Alexandria which, with its safe harbor and splendid library, became for a long time the most important center of Greek civilization and culture in the ancient world.
The third and the smallest division was Macedon, ruled by Autigonus and his successor, who had partial control over Greece till 146 B.C. In that, year Greece was made a Roman province under name of Achaea. Later, both Syria and Egypt were also conquered by the Romans.
Question: When Alexander died, his empire :