Gunnhild was widely reputed to have or otherwise employ magical powers. Prior to the death of Harald Fairhair, Erik's popular half-brother Halfdan Haraldsson the Black died mysteriously, and Gunnhild was suspected of having "bribed a witch to give him a death-drink." Shortly thereafter, Harald died and Erik consolidated his power over the whole country. He began to quarrel with his other brothers, egged on by Gunnhild, and had four of them killed, beginning with Bjørn Farmann and later Olaf and Sigrød in battle at Tønsberg.