Gordian knot

According to Greek mythology, when the peasant Gordius became king of Gordium in Phrygia, he dedicated his wagon to Jupiter and fastened its yoke to a beam with a very complex knot. Centuries later, when Alexander the Great arrived on the scene, he was told that he couldn't conquer and rule Asia unless he proved himself worthy by untying the knot. Alexander quickly solved his problem - and gained a new kingdom - by slicing the knot in half with his sword. Since then, "Gordian knot" has become a term for a difficult problem, and the phrase "cut the Gordian knot" has become a popular way to describe a neat solution for an apparently insurmountable difficulty.