First Stage - 431 to 421 BCE
The first stage, which dated from 431 to 421 BCE, is also termed as the Archidamian war. Minor breakthroughs were made by Athens on the Peloponnese by the naval way, and they caused the destruction of areas in Attica. Similarly, the expedition of Boeotia proved to be a disaster. Soon enough, Athens feared her allies would no longer support her.