 Various factions were at war.In mid-January 1213, William led the forces of Massa, Pistoia, the anti-Visconti faction in Pisa, and his father-in-law's militia to victory near Massa over the forces of Lucca supported by the Visconti under Ubaldo I, and by the deposed Pisan "podestà" Goffredo Musto.It was the greatest military accomplishment of William's career and is recounted in the "Ritmo lucchese".