This chapter focuses on less popularised aspects of Athenian hegemony and decline, starting from the capture of hegemony after the Persian wars, exploring specific strengths and weaknesses of the Athenian system, and debating the causes and the effects of that violent architect of hegemonic decline, the Peloponnesian war. The chapter sheds light on the disastrous effects of the hunt for regional hegemony and power for Ancient Greek city states, the role of political innovation through the establishment of knowledge networks in Ancient Athens, both as an enabling force to capture hegemony, but also as a factor for inciting fear and suspicion in Athens’ own allies, in their fluctuating relationship with Sparta and elsewhere, especially with the halt of that innovation by war, resulting in Athenian hegemonic decline.