He was consequently attacked by William II of Cagliari and Marianus II of Torres. They desired to maintain a condominium in Arborea, but internal fighting allowed Peter to solidify his authority with little opposition.
Peter's authority was threatened when he was attacked by William II of Cagliari and Marianus II of Torres, who wanted to maintain control over Arborea. However, internal conflicts allowed Peter to solidify his grip on the region with little resistance.