AYMER or AETHELMAR, OF VALENCE (d. 126o), bishop of Winchester, was a half-brother of Henry III., being the son of John's widow by her second marriage with Hugo of Lusig nan. In 12 5o, Henry III., the King, by putting strong pressure upon the electors, succeeded in obtaining the see of Winchester for Aymer. Aymer was illiterate, ignorant of the English lan guage, and wholly secular in his mode of life, and his appointment aroused justifiable indignation. At the Parliament of Oxford (1258) he and his brothers repudiated the new Constitution pre pared by the barons. He was pursued to Winchester, besieged in Wolvesey castle, and finally compelled to surrender and leave the kingdom. He had never been consecrated ; accordingly in 1 259 the chapter of Winchester proceeded to a new election.
BIBLIOGRAPHY.-See W. Stubbs, Constitutional History, vol. ii. Bibliography.-See W. Stubbs, Constitutional History, vol. ii. (1896) ; G. W. Prothero, Simon de Montfort (1877) ; W. H. Blaauw, Barons' War (1871) .