Prince, and later king Kistrin of Verden, son of king Ervyll, was first introduced in the short story "Miecz przeznaczenia" as a potential suitor for Ciri, hand-picked by Calanthe. This match did not work out. Ciri described him as "fat, ugly and stupid, with bad breath". His mother may have been Eliza, but that is not clearly established. Either way Freixenet is his uncle by marriage.
During the second war with Nilfgaard, he led insurgent troops from Verden and removed his own father from the throne, succeeding him as ruler. Ultimately he helped shape the peace treaty that ended the wars.