Boniface I, Marquess of Montferrat the independent city communes of the Lombard League. Boniface's eldest brother, William, had died in 1177, soon after marrying Sibylla, the heiress presumptive to the Kingdom of Jerusalem. In 1179, the Byzantine emperor Manuel I Comnenus offered his daughter Maria Porphyrogenita as a bride to one of the sons of William V. Since Boniface, like his older brother Conrad, was already married, and Frederick was a priest, the youngest brother, Renier, married her instead, only to be murdered along with her during the usurpation of Andronicus. In 1183, Boniface's nephew Baldwin V was crowned co-king of Jerusalem. William V went
Baldwin I, Latin Emperor empire, who received a large territory in Macedonia with the title of King of Thessalonica. Boniface hoped to make himself quite independent of the empire, to do no homage for his kingdom, and he opposed Baldwin's proposal to march to Thessalonica. The antagonism between Flemings and Lombards aggravated the quarrel. Baldwin insisted on going to Thessalonica; Boniface laid siege to Adrianople, where Baldwin had established a governor; civil war seemed inevitable. An agreement was effected by the efforts of Dandolo and the count of Blois. Boniface received Thessalonica as a fief from the emperor, and was appointed commander of the