Final answer:
Thucydides, a famous ancient Greek historian and veteran of the Peloponnesian War, authored 'The History of the Peloponnesian War,' a pivotal work analyzing the events and causes of the conflict between Athens and Sparta.
Step-by-step explanation:
The famous historian of ancient Greece who also fought in the Peloponnesian War to defend his city, Athens, against Sparta was Thucydides (460 - 404 BCE). Thucydides is sometimes considered the real "father" of history-writing. His work, "The History of the Peloponnesian War", provides a significant account of the war, meticulously following the events while examining human motivations and decisions behind those events. He is well-known for crafting an argument and defending it with historical evidence, a practice still essential in historical research today.
Thucydides' chronicle serves not only as an exhaustive study of the Peloponnesian War but also as an analysis of the political and ethical consequences of Athens' quest for power, leading to its downfall in 404 BCE. His approach set a precedent for how history would be studied and written about, establishing a standard method that involves sourcing and citing evidence to support historical theses.