 By its expansion into the interior of the island, Arborea ensured its long-term survival in the face of external foes.Next, William pressed his claims to Logudoro — derived from Hugh I of Arborea, who was a uterine brother of Marianus II of Logudoro — by arms.In 1259, he entered into a lifelong battle with the Doria of Genoa after the death of Adelasia, the last ruler of the native dynasty in Logudoro.