Alexander's death resulted in a twenty-year power struggle that divided his empire into several parts, including mainland Greece and Macedonia, Syria and Mesopotamia, and Egypt. By 280 B.C., new Hellenistic monarchies, whose leaders ruled by force and lacked Alexander's organizational ability, were fighting each other and suffering internal struggles as well.

In this period, parts of Greece were able to achieve some degree of autonomy within confederacies or leagues, most of which were governed by oligarchies. As the leagues became dominant, smaller political units, such as Athens, lost most of their political power. In this process, states of larger size and greater complexity replaced the polis.

The Hellenistic kingdoms mingled elements of Greek culture with Near Eastern cultures. Some of the kings founded colonies to establish garrisons in foreign territory, and in such places intermarriage between Greeks and non-Greeks became common. The Greek language spread and was used as the lingua franca for culture, commerce, and administration throughout the Near East. Greek art forms also became prevalent in the region. The old rigid form of social organization characteristic of the polis was discarded. Greek towns were now a part of a larger entity, based not on kinship or residence but on power and control. A new power elite arose, made wealthy by the conquests of vast new territories and the payment of tribute. At the same time, peasants suffered greatly from higher levies to support the upper class. The weakness of the agricultural producers combined with constant warfare among kingdoms to make the Greeks vulnerable to a new Mediterranean power, Rome.