Birna Bran was one of the wives of King Bran Tuirseach and the mother of his firstborn son, Svanrige. Little is known of her origins; she may originally have been taken captive in a raid. She despises Skellige’s traditions, above all the custom of electing kings instead of passing the crown from father to son.

In The Witcher 3

At Bran’s funeral, tradition expects the first wife to die on his pyre. Birna refuses, and a younger concubine takes her place instead. During the feast at Kaer Trolde in The King is Dead – Long Live the King, she calls herself Queen Mother and demands that the crown go to her son.

When the other jarls will not listen, she turns to murder. With the help of Arnvald, she has the feast’s drinks laced with blood and mushrooms, turning the berserkers present into killers, and sends Svanrige out of the hall just in time. Almost every candidate dies, except Cerys and Hjalmar.

In King’s Gambit, Geralt and Cerys trace the plot back to her. The proof is thin until Svanrige himself asks why she sent him away. Birna confesses and is condemned to be chained to a rock and left to die of thirst and hunger.