Thucydides (c. 460-c. 395 BC) was a Greek historian known for his History of the Peloponnesian War, which recounts the war between Athens and Sparta. This work earned him the reputation ”Father of Scientific History” because he determined to provide an unbiased account, gathering evidence to find the causes and effects of the war rather than referring to the gods for explanations. He may also have been the first political realist, describing the victors as those who had superior numbers or power rather than those with greater morals or righteousness.