Wars of the Diadochi
Seleucus soon turned his attention once again eastward. The Persian provinces in what is now modern Afghanistan, together with the wealthy kingdom of Gandhara and the states of the Indus Valley, had all submitted to Alexander the Great and become part of his empire. When Alexander died, the Wars of the Diadochi ("Successors") split his empire apart; as his generals fought for control of Alexander's empire. In the eastern territories, Seleucus I Nicator took control of Alexander's conquests. According to the Roman historian Appian: