The war with Genoa and the Lombard towns increasingly occupied Charles' attention. He appointed his nephew Robert II of Artois as his deputy in Piedmont in October 1274, but Artois could not prevent Vercelli and Alessandria from joining the Ghibelline League. The following summer, a Genoese fleet plundered Trapani and the island of Gozo. Convinced that only Rudolf I could achieve a compromise between the Guelphs and Ghibellines, the Pope urged the Lombard towns to send envoys to him. He also urged Charles to renounce Tuscany. In the autumn of 1275 the Ghibellines offered to make peace with Charles, but he did not accept their terms. Early the next year the Ghibellines defeated his troops at Col de Tende, forcing them to withdraw to Provence.