1911 Encyclopædia Britannica/Æthelbald (king of Mercia)
ÆETHELBALD, king of Mercia, succeeded Ceolred A.D. 716. According to Felix, Life of St Guthlac, he visited the saint at Crowland, when exiled by Ceolred and pursued by his emissaries before his accession, and was cheered by predictions of his future greatness. According to Bede, the whole of Britain as far north as the Humber was included within the sphere of his authority. His energy in preserving his influence is shown by several entries in the Chronicle. He made an expedition against Wessex in 733, in which year he took the royal vill of Somerton. In 740 he took advantage of the absence of Eadberht of Northumbria in a campaign against the Picts to invade his kingdom. In 743 he fought with Cuthred, king of Wessex, against the Welsh, but the alliance did not last long, as in 752 Cuthred took up arms against him. In 757 Æthelbald was slain by his guards at Seckington (Warwickshire) and buried at Repton. He seems to have been the most powerful and energetic king of Mercia between Penda and Offa. A letter of St Boniface is preserved, in which he rebukes this king for his immoralities and encroachments on church property, while recognizing his merits as a monarch. By a charter of 749 he freed ecclesiastical lands from all obligations except the trinoda necessitas.
See Bede, Hist. Ecc. (ed. Plummer), v. 23 and Continuatio s.a. 740, 750, 757; Saxon Chronicle (Earle and Plummer), s.a. 716, 733, 737, 740, 741, 743, 755; Mabillon, Acta Sanctorum, ii. pp. 264, 273, 276, 4-9, W. de G. Birch, Cartul. Saxon. 178 (1885-1893).