Final answer:
Pericles financed his building program through the Delian League's treasury, which originated as a mutual defense fund against Persia but ultimately helped Athens prosper during the Periclean Revival.
Step-by-step explanation:
Pericles funded his extensive building program, which included magnificent structures such as the Parthenon, through the resources of the Delian League. Following the Persian Wars, Athens became the leader of this league of Greek city-states that contributed funds, ostensibly for defense against Persia. Pericles had the treasury moved to Athens and used this wealth not only for the city's defense but also significantly for cultural and architectural projects during the Periclean Revival.
The financial strategy of Pericles also allowed for the growth of Athenian democracy and bureaucracy. There was a payment of public servants which permitted even the poorer citizens to serve in public office, enhancing fairness and opportunity within the political system. Moreover, it was the employment from the Delian League's treasury that financed jobs for many Athenians, including rowers in the fleet and jurors in the courts, further stabilizing the city's economy.
While these projects led to a Golden Age for Athens, signified by cultural prosperity and democratic advancements, they also contributed to the strain in Athens' relationship with other Greek city-states who saw this use of the common funds as overreach and despotism.