Explain how Pericles was an imperialist.

In the late 400s B.C., several Greek city-states formed what was known as the Delian League, a loose alliance system, to meet the threat posed by the invading Persian Empire. After defeating the Persians, the League became permanent, and it was always dominated by Athens, the most powerful city-state. In the years that followed, Athens began to attempt to convert the Delian League into an empire. As the chief statesman and political leader in Athens, Pericles was at the center of these efforts. He used the treasury of the Delian League to pay for Athenian building projects (including the Parthenon) and launched several military expeditions to expand the influence of Athens. The ancient Greek historian Thucydides fairly explicitly describes Pericles as an imperialist who boasted about all of the Greeks ruled by Athens. He viewed Athenians as culturally superior to other Greeks, especially the Spartans. Indeed, Athenian expansionism under the guidance of Pericles was a major contributing factor to the outbreak of the Peloponnesian War, a highly destructive and lengthy conflict between alliances led Athens and Sparta. Pericles himself died during this war, which ultimately resulted in a catastrophic defeat for the Athenians. This war brought the "golden age" of Athens, one characterized as much by imperialist expansion as by democracy and high culture, to an end. Pericles is identified with each of these characteristics.