Gordian Knot.

Chambers's Encyclopaedia, Volume 5: Friday to Humanitarians, p. 300

Gordian Knot. The traditional origin of this famous knot was as follows. The Phrygians, seeking a king, were informed by the oracle at Delphi that they were to choose the first person they met riding on an ox-cart towards the temple of Zeus. That person was Gordius, a poor peasant, who accordingly was elected king. He afterwards dedicated his car and yoke to Zeus, in the acropolis of Gordium (a city named after himself), and tied the knot of the yoke in so skilful a manner that an oracle declared whoever should unloose it would be ruler of all Asia. When Alexander the Great came to Gordium, he cut the knot in two with his sword and applied the prophecy to himself.

Source scan(s): p. 0311