The most famous knot in history is the Gordian Knot. According to legend, in ancient Phrygia (in what is now Turkey) a farmer named Gordius became king because he was able to tie a knot so complicated that no one could untie it. He attached the knot to the yoke of his ox-cart, and an oracle prophesied that whoever could untie the knot would become the ruler of all of Asia.
Many tried and failed to untie the knot, until Alexander the Great came along. Alexander was not interested in untying the knot the traditional way. Instead, he drew his sword and cut through it, thereby conquering the kingdom.