Legend has it that an eagle once landed on the ox-cart of a poor Phrygian (central Asia minor) man named Gordias. Amazed by this sign, Gordias consecrated the ox-cart to the Phyrgian god Sabazios - the god corresponding to Zeus in the Greek pantheon. The shaft of the ox-cart was tied with an intricate knot to commemorate this ominous event.
Many years later, the Phrygians were without a ruler. A Phrygian seer declared that the next man to enter the city gates on an ox-cart should become next king of the Phyrgians. Ahmidas, the son of Gordias, unsuspectingly drove his ox-cart, the one bearing the knot, through the gates. Ahmidas son of Gordias was crowned king of the Phrygians and established his dynasty. The seers stated that the man who could untie Gordias' knot on the ox-cart would be next king of Phrygia.
Alexander the Great arrived in Phrygia in 333 BC. While spending the winter at Gordion, he was challenged to untie the famous Knot of Gordias. Alexander attempted to untie the Gordian knot, but he could not find the end of the cord. Unable to unbind the knot, Alexander sliced the knot with his sword and loosened the Gordian Knot. He went on to conquer the Phrygians and all of Asia Minor.
Today, "cutting the Gordian knot" refers to someone who quickly solves a problem by thinking outside of the box.