Gordian Knot, a legendary knot that became a metaphor for an intractable problem solved by a bold stroke.
The Gordian Knot is a legend of Phrygian Gordium associated with Alexander the Great. It is often used as a metaphor for an intractable problem solved easily by cheating or “thinking outside the box”. (“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, Act 1 Scene 1. 45–47)