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
Philip I, Count of Flanders brother-in-law, intervened in 1184 on behalf of his son-in-law, King Philip, in support of his daughter's interests. The dispute between Count Philip and Baldwin was encouraged by King Philip, who went so far as to name Baldwin his representative in negotiations with the Count. Count Philip's wife, Elisabeth, died in 1183, prompting King Philip II to seize the province of Vermandois on behalf of Elisabeth's sister, Eleonore. Philip then remarried, to Matilda, daughter of Afonso I, the first King of Portugal. Philip gave Matilda a dower that included a number of major Flemish towns, in an apparent slight to Baldwin