Neither the tunny nor the coral fishery is carried on by the Sardinians themselves, who are not sailors by nature; the former is in the hands of Genoese and the latter of Neapolitans.
The Pisans took up the challenge, and Musat was driven out of Cagliari with the help of the Genoese in 1022 for the third time.
The Pisans and Genoese now disputed about the ownership of Sardinia, but the pope and the emperor decided in favour of Pisa.
After this the Pisan supremacy of the island seems to have become more of a reality, but Arborea remained independent, and after the defeat of the Pisans by the Genoese at the naval battle of Meloria in 1284 they were obliged to surrender Sassari and Logudoro to Genoa.
We find them also at war with many of these powers, and with the Genoese, who endeavoured to monopolize the commerce of the Black Sea.