The evil sovereigness of the Ancient Tower in La Tavola Ritonda.
She was the daughter of Trincardo the Mad and the sister of Pinabel and Uriées. Pinabel had slain Uriées so he could marry a maiden named Tessina. Losanna’s family swore to avenge the murder, killed Pinabel, and brought Tessina to the Ancient Tower for execution.
Tristan saved the lady. Sir Dinadan fell in love with Losanna and tried to reclaim Tessina from Tristan, but failed.
See also
Lanfate | The Legend of King Arthur
Source
La Tavola Ritonda | 1325–1350