Aymer of Valence (ā´mər, vəlĕns´, väläNs´), d. 1260, bishop of Winchester; son of Isabella (widow of King John of England) and Hugh X, count of La Marche. He was thus half-brother of King Henry III of England. He is sometimes called Æthelmar. Henry forced the chapter of Winchester to elect Aymer bishop in 1250, but his youth and ignorance, combined with his disinclination to assume the responsibilities along with the revenues of office, delayed his consecration. He was one of the king's 12 delegates in formulating the Provisions of Oxford. However, he refused to swear to them, and hostility toward him and his brothers was an important factor in the Barons' War. Later he and his brothers had to flee the continent. Aymer was consecrated by the pope in 1260 and was on his way back to England when he died in Paris.

Æthelmar of Valence: see Aymer of Valence.