BOHEMUND I. (c. A.D. 1058-11I1), prince of Otranto and after wards of Antioch, was the eldest son of Robert Guiscard, by an early marriage contracted before 1059. He served under his father in the great attack on the East Roman empire (1080-85), and commanded the Normans during Guiscard's absence (1082-84), penetrating into Thessaly as far as Larissa, but being repulsed by Alexius Comnenus. This early hostility to Alexius had a great in fluence in determining the course of his future career, and thereby helped to determine the history of the First Crusade. On the death of Guiscard in 1o85, his younger son Roger succeeded to the duchy of Apulia and Calabria, and a war arose between Bohemund and Duke Roger. The war was finally composed by the mediation of Urban II. and the award of Otranto and other possessions to Bohemund. In 1096 crusaders began to pass on their way through Italy to Constantinople, and Bohemund joined the crusade. He gathered a fine Norman army, at the head of which he crossed the Adriatic, and penetrated to Constantinople along the route he had tried to follow in 1082-84. At Constantinople he did homage to the emperor. From Constantinople to Antioch Bohemund was the real leader of the First Crusade. He took a great part in the siege of Antioch (1097-98), beating off the Mohammedan at tempts at relief from the east, and connecting the besiegers on the west with the port of St. Simeon and the Italian ships which lay there. The capture of Antioch was due to his connection with Firuz, one of the commanders in the city ; but he would not bring matters to an issue until the possession of the city was assured him (May 1098), under the terror of the approach of Kerbogha with a great army of relief, and with a reservation in favour of Alexius, if Alexius should fulfil his promise to aid the crusaders. But Bohe mund was not secure in the possession of Antioch, even after its surrender and the defeat of Kerbogha; he had to make good his claims against Raymund of Toulouse, whom he had alienated, and who was now the ally of Alexius. He obtained full possession in Jan. I099. Bohemund went to Jerusalem at Christmas 1099, and had Dagobert of Pisa elected as Patriarch, perhaps in order to check the growth of a strong Lotharingian power in the city. It might seem in IIoo that Bohemund was destined to found a great principality in Antioch, which would dwarf Jerusalem ; he had a fine territory, a good strategical position and a strong army. But he had to face two great forces—the East Roman empire, which claimed the whole of his territories and was supported in its claim by Raymund of Toulouse, and the strong Mohammedan principalities in the north-east of Syria. Between these two forces he failed. In I ioo he was captured by Danishmend of Sivas, and he languished in prison till 1103. His nephew Tancred took his place ; but meanwhile Raymund established himself with the aid of Alexius in Tripoli, and was able to check the expansion of Anti och to the south. Ransomed in 1 103 by the generosity of an Ar menian prince, Bohemund attacked the neighbouring Mohamme dan powers in order to gain supplies, but was severely defeated at Balich, near Rakka on the Euphrates, and despairing of his own resources, returned to Europe for reinforcements. There he won the hand of Constance, the daughter of the French king, Philip I., and collected a large army. Instead of defending Antioch with this army he attacked Alexius, who, aided by the Venetians, proved too strong; and after the unsuccessful siege of Durazzo, Bohemund had to submit to a humiliating peace at Deabolis (11o8), by which he became the vassal of Alexius, consented to receive his pay, with the title of Sebastos, and promised to cede disputed territories and to admit a Greek patriarch into Antioch. Bohemund was buried at Canossa in Apulia, in anonymous Gesta Francorum (ed. H. Hagen meyer) is written by one of Bohemund's followers; and the Alexiad of Anna Comnena is a primary authority for the whole of his life. See also B. von Kugler, Bohemund and Tancred (Tubingen, 1862) ; L. von Heinemann, Geschichte der Normannen in Sicilien and Unter italien (Leipzig, 1894) ; R. Rohricht, Geschichte des Konigreichs Jeru salem (Innsbruck, 1898) and Geschichte des ersten Kreuzzuges (Inns bruck, 19o1).