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 IV of Jerusalem support of Agnes and her husband Reginald of Sidon, Raymond, and many of the other barons, excluding Sibylla from the succession. Raymond was to act as guardian of the infant heir, and later as regent if Baldwin IV was to expire, but Baldwin IV himself would continue to rule. The child was crowned co-king as Baldwin V on November 20, 1183. In the early months of 1184, Baldwin attempted to have the marriage between Sibylla and Guy annulled. This was foiled by their holding fast in Ascalon, Guy refusing to attend the annulment proceedings. The military expedition to relieve Karak