Solon (594 BC), Cleisthenes (508/7 BC), and Ephialtes (462 BC) contributed to the development of Athenian democracy. Cleisthenes broke up the power of the nobility by organizing citizens into ten groups based on where they lived, rather than on their wealth. The longest-lasting democratic leader was Pericles. After his death, Athenian democracy was twice briefly interrupted by oligarchic revolutions towards the end of the Peloponnesian War. It was modified somewhat after it was restored under Eucleides; the most detailed accounts of the system are of this fourth-century modification, rather than the Periclean system. Democracy was suppressed by the Macedonians in 322 BC. The Athenian institutions were later revived, but how close they were to a real democracy is debatable.