Pericles came from the aristocratic line of the Alcmaeonids. He was the son of Xanthippus and Agariste and a descendant of Cleisthenes. In 472 B.C. he made his first official appearance in Athenian political life as choregos of The Persians by Aeschylus. He became more widely known in 463/2 B.C. when he disagreed with Cimon’s policies, and a year later he gave his support to the reforms of Ephialtes. He also undertook the construction of many buildings in Athens, which bolstered his political position and contributed to his popularity, helping to secure his annual re-election as general from 433 B.C. to 429 B.C., with the exception of one year, 430 B.C.

His popularity grew in the decade 450-440 B.C., during which his main preoccupation was the establishment of the democratic constitution. As far as foreign affairs were concerned, he contributed to the transformation of the Delian League into an Athenian hegemony - hence his initiative of calling a Panhellenic conference in Athens. However, it never succeeded due to the opposition of the Lacedaemonians and the Peloponnesian League. During the Peloponnesian War his strategy was defensive, and turned on bringing the Athenians within the city walls and relying on the navy for offensives against Sparta..