In exchange for Goceano, Comita considered siding with Pisa and expelling the Genoese from his giudicato, as well as relinquishing his claims to Arborea.

In an ensuing peace treaty with Cagliari, Marianus, Comita's heir, married Agnes of Massa, William's daughter, who brought with her Goceano as a dowry.

After that, with the support of Innocent, they invaded Arborea, an invasion which ended in the partition of the realm: half going to Barisone III, son of Peter I, and a quarter each going to Comita and William of Cagliari.

Lamberto and Ubaldo I Visconti took the opportunity that year to launch an offensive at Gallura, Cagliari, and Arborea, but were beaten off by Comita and Genoa.

The war continued at sea, but was arrested by the entreaties of Pope Honorius III, who forced Comita to come to terms with Pisa (1 December 1217).