How did the Peloponnesian War Happen? - Athens Faces Sparta (431–404 BC)

Sparta and Athens. Names recognizable across the globe. They were once the powerhouses of Ancient Greece, and it was the quarrel between these two entities, particularly that so stunningly brought about the end of the Golden Age for Greece. So what was it that pitted the mighty Athens against the steamrolling Spartans? How did these all-powerful city-states cause so much damage to an entire region?