William VI of Montferrat

William VI (c. 1173–1226), son of Marquis Boniface I and Elena del Bosco, ruled Montferrat from 1207. On his father’s death in the Fourth Crusade, he kept Montferrat while his half-brother Demetrius inherited Thessalonica. He abandoned the Guelph emperor Otto IV for Frederick II, escorting Frederick from Genoa in 1212.

He took the cross to relieve Thessalonica, but enemies in Piedmont and financial difficulties delayed him, and in 1224 he pledged his marquisate to Frederick. Reaching Greece, he died near Almyros on 17 September 1226, his army wasted by dysentery. Berta di Clavesana’s son succeeded as Boniface II.