Bohemund IV was the son of Bohemund III of Antioch by his second wife Orguilleuse. The first part of his rule was marked by internal dynastic conflicts. Bohemund III had grandson, Raymond-Roupen of Antioch, from Raymond of Antioch his eldest son, who was considered by many as the rightful heir to Antioch. Despite the fact that Raymond-Roupen was excluded from the succession, Bohemund IV lost the principality to his nephew, supported by Leo II of Armenia, between 1216 and 1219.
Bohemund proved to be an erractic ally, changing his vows of fidelity in whichever way he considered the best interest for his principality. An example was first the alliance then desertion of the troops of Frederick II Hohenstauffen, during the Sixth Crusade of 1228/1229. He was also a fierceful enemy of the Knights Hospitaller and due to this he was excommunicated in 1230 by Pope Gregory IX.
Bohemund married Plaisance of Gibelet and had at least three sons: Henry of Antioch (father of king Hugh III of Cyprus and I of Jerusalem), Philip of Antioch, who married Isabella of Armenia, and Bohemund, who succeeded him.
The so-called Latin Patriarchate of Antioch owes its origins to the times of the Crusades of the eleventh, twelfth, and thirteenth centuries, in connection with the Latin Patriarchate of Jerusalem, both of which nowadays are simply titular, without any jurisdiction, and their titulars reside in Rome.
BohemondIV, however, soon began to intrigue to replace him with the Greek Patriarch, Simeon III; but he was excommunicated by the Patriarch and by the pope himself, Innocent III, which caused the whole Latin clergy to rebel against the king.
Pietro d'Amalfi, nevertheless, was imprisoned by Bohemond and died in 1208, and was succeeded by the Latin Bishop of Jerusalem, Pietro d'Capoa, nephew of the deceased patriarch.