Dictionary of National Biography, 1885-1900/Sigebert (d.756?)
SIGEBERT (d. 756?), king of the West-Saxons, son of Sigeric, an under-king of the West-Saxons, succeeded his kinsman Cuthred [q. v.] in 754 or 755. He was a bad ruler, for he was proud, cruel, and corrupt. At the beginning of the second year of his reign his nobles and people rose against him, and he was deposed by a formal act of the West-Saxon witan, who chose Cynewulf [q. v.] to reign in his stead. For a while he was allowed to retain Hampshire, where he was supported by the ealdorman Cumbran. As, however, he did not amend his ways, Cumbran remonstrated with him in the name of his people, and was in consequence unjustly put to death by him. This act lost him Hampshire. He fled, and was pursued by Cynewulf. He took shelter in the forest of Andred, and was there at Privets-flood (Privet is in Hampshire, near Petersfield), perhaps in 756, slain with a spear by a swineherd of Cumbran in revenge for his master's death. Many years later Sigebert's brother Cyneheard slew Cynewulf.
[Anglo-Saxon Chron. an. 754; Mon. Hist. Brit. p. 641; Hen. Hunt. p. 123, Sym. Dunelm. Hist. Regum, an. 577, ap. Opp. ii. 40, Rog. Hov. i. 21 (these three Rolls Ser.); Dict. Chr. Biogr. art. ‘Sigebert’ (7), by Bishop Stubbs.]