Short answers, pulled from the story.
Thucydides was an Athenian historian and general who wrote about the Peloponnesian War that began in 431 BC. He documented events including the plague that killed Pericles and many other Athenians while serving as a strategos sent to Thasos.
In 424 BC, Thucydides served as a strategos sent to Thasos before being exiled for failing to save Amphipolis from Spartan control. The fall of Amphipolis occurred during the winter of 424, 423 BC when Brasidas attacked the city.
After exile, Thucydides took up permanent residence on an estate at Scapte Hyle where he owned gold mines opposite the island of Thasos. This location provided income that allowed him to dedicate himself to full-time history writing and research until his death around 397 BC or slightly later.
Thucydides declared his intention was to write an account which would serve as a possession for all time rather than rehearsed for festivals. Unlike Herodotus who recorded fables and passed no definitive judgment, Thucydides confined himself to factual reports based on unambiguous first-hand eyewitness accounts without acknowledging divine intervention.
Pausanias wrote that someone named Oenobius passed a law allowing Thucydides to return to Athens shortly after the war ended in 404 BC. Plutarch preserved a tradition that Thucydides was murdered on his way back to Athens before he could officially return.