King Croesus of Lydia (a Greek colony in the Ancient Near East) tried to conquer Persia. He was defeated by King Cyrus of Persia. Ever since then, Persia tried to conquer Greece in a few different invasions. Darius of Persia tried to invade Greece, but was defeated at Marathon. Xerxes of Persia invaded Greece later, with a massive army, and conquered northern Greece, until his army was defeated at Plataea. After the defeat of Persia, Greece formed the Delian league under Athens, to raise armies to liberate the rest of Greece and Greek colonies from Persian rule. Over time, rivalries grew between Athens and Sparta, with Sparta organizing and leading the Peloponnesian league. War broke out between the two leagues, Greece was weakened by the war, and Macedonia exploited that weakness to invade and conquer Greece, under King Phillip. After Phillip died, his son Alexander inherited the rule of Greece, and he led the combined armies of Greece against Persia, partly to avenge the burning of Athens by Xerxes' army. Alexander defeated Persia's armies, conquered pretty much the entire Persian Empire, and got as far east as India before turning back.