In Chrétien’s Cligés, this potentate betrothed his daughter Fenice to the Duke of Saxony, but jumped at the chance to break this engagement and give her to Emperor Alis of Greece and Constantinople instead.
This caused plenty of fighting, which might have been seen a further political shrewdness in an age when knights often enough hacked away at one another for far less reason.
See also
Germany | The Legend of King Arthur
Ratisbonne | The Legend of King Arthur
Source
Cligés | Chrétien de Troyes, late 12th century