As told in the Apology--one of the best-known works of Greek philosophy and literature--the trial that led to the death of Socrates was dramatic. Socrates' reasoning and philosophy, and the questions they raised not only about ephemeral things but also political, moral, and legal matters, drew the ire of the leaders of the Athenian polis who, fearing he was leading the young people of the Athens astray. An ambitious young Athenian, Meletus (with Anytus and Lycon), led the prosecution against Socrates, who accused Socrates of being "a doer of evil, who corrupts the youth; and who does not believe in the gods of the state, but has other new divinities of his own." (The Apology of Socrates)
A trial, before a jury of 501 Athenian citizens was held in which Socrates called into question the whole basis for the trial, instead of putting on a self-abasing, eloquent defense, which was expected. By a very narrow margin, the Athenians found Socrates guilty. Next, Socrates and his prosecutor suggested competing sentences. Socrates jokingly suggested free meals, but then finally settled on an insultingly small fine. His prosecutor urged death. The Athenians held a second vote, on the sentences. The verdict was nearly unanimous (60 to 441), but this time on a matter of principle: guilty men must be punished. Socrates' followers encouraged him to flee, and indeed the city fathers expected this and were probably not averse to it; but he refused on principle, and took the poison (hemlock) himself. He was, thus, one of the first of a limited number of strictly intellectual "martyrs". Socrates died at the age of 70.
Athenian trials did not have judges, merely juries. At the time Athens had been going through some difficult times, and the attack on Socrates was due in large part to Critius, a member of the tyrants, and Alcibiades, an aristocrat who defected in the Peloponnesian war, had both been close associates of Socrates, and he himself was a critic of democracy - but remained loyal, and never condoned the tyranny. All in all, though, it was a dangerous time to be the sort of man that Socrates was.