prince of Otranto (1089–1111) and prince of Antioch (1098–1101, 1103–04), one of the leaders of the First Crusade (Crusades), who conquered Antioch (June 3, 1098).

The son of Robert Guiscard (the Astute) and his first wife, Alberada, Bohemond was christened Marc but nicknamed after a legendary giant named Bohemond. The nickname proved well taken because physically Bohemond was the ideally tall and strong knight—in the words of a contemporary, “a wonderful spectacle.” His boyhood home was in southern Italy, where his Norman father, Robert, had gone as a mercenary and had risen to the rank of duke of Apulia and Calabria. Here Bohemond became involved in his father's wars and learned his trade as a fighter and leader. This early training must be inferred, however, as Bohemond's childhood is poorly recorded, and even his date of birth is unknown. In 1079 he was in command of a unit of his father's army. Meanwhile his stepmother, Sigelgaita, bore his father's heir-to-be, Roger Borsa; thus, Bohemond no doubt felt early in life that he would have no patrimony because of his half brother and so would have to seek lands and fortune in the weakened condition of the Byzantine Empire.

In 1081 Bohemond, in command of his father's army, captured Avlona, a town south of Durazzo; but in this same year Alexius I Comnenus became ruler of the Byzantine Empire and challenged the Normans (Norman). For more than three decades Alexius and Bohemond were rivals. In the opening struggle, 1081–85, Bohemond and his father came close to dismembering the Greek empire in the West. The Norman army won a few brilliant victories, but Alexius drove Bohemond from Larissa in Thessaly in 1083, and the death of Robert in 1085 left Bohemond without a patrimony and with little hope of success against Byzantium. In the next four years Roger Borsa allowed Bohemond to gain a foothold in Bari, where he awaited another chance to move against Alexius.

The chance came when Pope Urban II (Urban II) launched the First Crusade (Crusades) in November 1095 by offering rewards in both this world and the next for those who wrested the Holy Sepulchre from the Saracens. When the word reached Bohemond, he set off for the East. He and his small band of Normans crossed the Greek lands in the winter of 1096–97 with few incidents; on passing through Constantinople (now Istanbul), he made friendly, though cautious, terms with the emperor Alexius. The latter managed to extract oaths from most of the leaders, including Bohemond, and helped them cross the Bosporus, speeding them with promises of aid if they would return to the sovereignty of the emperor the Byzantine lands recaptured from the Muslims. In the ensuing campaigns against the Turks (Seljuq), Bohemond distinguished himself at Nicaea, Dorylaeum, and Antioch, which was besieged from October 1097 until June 3, 1098. The city of Antioch fell to the Crusaders through his cunning and his negotiations with a traitor. After a brief, unsuccessful countersiege by the Turks, during which Bohemond more or less assumed command, the Crusaders dawdled away the summer and fall.

When the Crusading army marched southward to Jerusalem in January 1099, Bohemond was left the de facto possessor of Antioch, although his claim was not openly supported for fear of violating the oath of Alexius. The Norman leader did not participate in the capture of Jerusalem but did, for the sake of appearances, journey later to the Holy Sepulchre. With the departure of many Crusaders for their homelands, Bohemond was left with his city. It might seem that Bohemond in 1100 was destined to found a great principality in Antioch; he had a fine territory, a good strategical position, and a strong army. But he had to face two great forces—the Byzantine Empire, which claimed the whole of its territories, and the strong Muslim principalities in the northeast of Syria. Between these two forces he failed. Following sorties against Aleppo, Bohemond made the mistake of moving against the emir of Sebastea (Sivas), north of Antioch. He fell into an ambush and was captured and held for months.

Released in 1103, he returned to Antioch and its problems. In 1105 Bohemond was in Bari to enlist reinforcements for his struggle with the Byzantines. In September 1105 he went to Rome to interview the pope and then journeyed, early in 1106, through France. There babies were named for him, crowds heard him denounce the perfidious Alexius, and shrines received sacred relics from his hands. In the spring of 1106 Bohemond married Constance, the daughter of Philip I of France.

Bohemond, who 30 years before had been a landless young man, now stood at the pinnacle of his career. By September 1107 he was ready to launch his Crusade against the Byzantines and within a month had landed a large army at Avlona. In the months that followed, Durazzo held firm against the Normans, and Bohemond met with misfortune in Albania. In this impasse Alexius, anxious to end the war, offered Bohemond Antioch and other Greek cities in return for vassalage. In accepting these terms, Bohemond suffered humiliation even though he retained control of Antioch.

The years following this peace of discord are poorly recorded. Constance bore Bohemond two sons, one of whom later became prince of Antioch. Bohemond probably sought to raise another army, but these efforts ended with his death in 1111. His combat with the Byzantines was ended, and his rival Alexius followed him in death in 1118. Nicknamed for a giant, Bohemond had fought against gigantic odds and at death bequeathed to his heirs one of the important Crusader states, the principality of Antioch. History records him as a handsome man, a warrior of genius, and a gifted diplomat. He was all these things, as well as treacherous, duplicitous, and ambitious.