William VI, Marquis of Montferrat

On 12 June 1199, he was put in charge of Acqui Terme with twenty knights to combat the Alessandrini, and, on 27 October, he was present near Saluggia for the signing of a pact with the commune of Vercelli.

Though William expected to see the power of an emperor levelled against his foes, the only aid he received from Otto was directed against small local potentates which posed little real threat.

At the Diet of Lodi, William abandoned Otto finally in favour of Frederick II, the Hohenstaufen claimant.

Following his father's death in 1207, his conquests in Greece, formed into the Kingdom of Thessalonica, passed into the hands of William's half-brother Demetrius.

The succession was opposed by the Lombard nobles of the kingdom, led by the regent Oberto II of Biandrate, who preferred the crown to pass to William.

William himself was reluctant to claim the throne, and with the support of Latin Emperor Henry of Flanders, the rebellion of the Lombard barons was overcome, and Demetrius was crowned king.

During the exhausting years battling rebels and Guelphs, William at last resolved to travel to Greece to defend the conquests of his father.

But the arrival of Demetrius, fleeing the onslaught of the Greeks under Theodore Komnenos Doukas and the hostility of the Lombard barons, led by Biandrate, convinced him to go to Greece.