বায়োগ্রাফি : Thucydides (c.  460 – c.  400 BC) is known as the father of “scientific history” and political realism. He was born to Olorus was an Athenian historian and general in the Peloponnesian War. Thucydides developed an understanding of human nature to explain behavior in such crises as plagues, massacres, and civil war. His famous works include History of the Peloponnesian War. His works are still studied in universities and military colleges worldwide.