The historian who wrote a history of the war between Sparta and Athens (so called Peloponnesian war) was Thucydides. Thucydides was Athenian historian, political philosopher and general. One of his most important works was 'History of Peloponnesian War', in which he described an ancient Greek war between Athens and its empire and the Peloponnesian League led by Sparta in 5th cntury BC. Thucydides is considered to be 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. He has also been called the father of the school of political realism.