Historian of the Peloponnesian War, born in Athens nine years after the battle of Salamis, of a wealthy family; was in Athens during the plague of 430 B.C.; was seized, but recovered; served as naval commander in 424 in the Peloponnesian War, but from neglect of duty was banished; returned from exile 20 years after; his great achievement is his history, all derived from personal observation and oral communication, the materials of which were collected during the war, and the whole executed in a style to entitle it to rank among the noblest literary monuments of antiquity; it is not known how or when he died, but he died before his history was finished.