Thucydides was an Athenian historian, political philosopher and general. His History of the Peloponnesian War recounts the 5th century BC war between Sparta and Athens to the year 411 BC. Thucydides has been called the father of "scientific history" because of his strict standards of evidence-gathering and analysis of cause and effect without reference to intervention by the gods, as outlined in his introduction to his work. The History of the Peloponnesian War is a historical account of the Peloponnesian War (431–404 BC), which was fought between the Peloponnesian League (led by Sparta) and the Delian League (led by Athens). His account of the conflict is widely considered to be a classic and regarded as one of the earliest scholarly works of history. The History is divided into eight books.