The document summarizes the Peloponnesian War between Athens and Sparta that lasted over 25 years. It began as a minor quarrel between the two city-states but escalated into a major war. Though Athens initially dominated by sea, Sparta built a navy with Persian gold and began to gain ground. A plague killed over half of Athens' population. After years of conflict, Athens surrendered in 404 BCE, ending its democracy and independence. The war weakened all of Greece and paved the way for Macedonia to rise in power under Alexander the Great.