Ancient Greece consisted of a number of city-states, each with their own laws and customs. No single ruler existed until Phillip II united Macedonia and most of Greece in 360 B.C.
Phillip's son, Alexander III, also called Alexander the Great, is one of the most famous rulers of ancient Greece. He invaded the Persian empire and conquered much of the civilized world between 333 B.C. and 326 B.C. Other famous rulers include Pericles (died 429 B.C.), who ordered the building of the Parthenon and advanced democracy in Athens, and Epaminondas (410 B.C. to 362 B.C.), who lead the city-state of Thebes from Spartan subjugation to a position of importance in Greek politics.