The Archaic Period in Greece is generally considered to have lasted from around the eighth century BC to the invasion by Xerxes in 480 BC. This period saw the expansion of the Greek world around the Mediterranean, with the founding of Greek city-states as far afield as Sicily in the West and the Black sea in the East. Politically, the Archaic period in Greece saw the collapse of the power of the old aristocracies, with democratic reforms in Athens and the development of Sparta's unique constitution. The end of the Archaic period also saw the rise of Athens, which would come to be a dominant power in the Classical period, after the reforms of Solon and the tyranny of Pisistratus.