The Gordian Knot is a legend associated with Alexander the Great. It is often used as a metaphor for an intractable problem, solved by a bold stroke ("cutting the Gordian knot"):
"Turn him to any cause of policy,
The Gordian Knot of it he will unloose,
Familiar as his garter" (Shakespeare, Henry V, 1.i)
In 333 BC, while wintering at Gordium, Alexander attempted to untie the knot. When he could find no end to the knot, to unbind it, he sliced it in half with a stroke of his sword, producing the required ends (the so-called "Alexandrian solution", taken by the Hellenic Army IV Army Corps as their motto). Once Alexander had sliced the knot with a sword-stroke, his biographers claimed in retrospect that an oracle further prophesied that the one to untie the knot would become the king of Asia.
Plutarch disputes the claim that Alexander sliced the knot with his sword, and relates that according to Aristobulus, Alexander pulled the knot out of its pole pin rather than cutting it. Either way, Alexander did go on to conquer Asia as far as the Indus and the Oxus, fulfilling the prophecy.
Unlike fable, true myth has few completely arbitrary elements. This myth taken as a whole seems designed to confer legitimacy to a dynastic change in this central Anatolian kingdom: thus Alexander's "brutal cutting of the knot... ended an ancient dispensation. The ox-cart seems to suggest a longer voyage, rather than a local journey, perhaps linking Gordias/Midas with an attested origin-myth in Macedon, of which Alexander is most likely to have been aware. To judge from the myth, apparently the new dynasty was not immemorially ancient, but had widely remembered origins in a local, but non-priestly "outsider" class, represented by the peasant Gordias in his ox-cart. Other Greek myths legitimize dynasties by right of conquest (compare Cadmus), but the legitimizing oracle stressed in this myth suggests that the previous dynasty had been a race of priest-kings allied to the oracle deity.