E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Ring of Invisibility (The),
which belonged to Otnit, King of Lombardy, given to him by the queen-mother when he went to gain in marriage the soldans daughter. The stone of the ring had the virtue of directing the wearer the right road to take in travelling. (The Heldenbuch.) (See GYGES RING.)