COURCI, JOHN DE (d. 1219?), Anglo-Norman conqueror of Ulster, was a member of a celebrated Norman family of Ox fordshire and Somersetshire. It appears that he accompanied William FitzAldelm to Ireland when the latter, after the death of Strongbow, was sent thither by Henry II., and that he immediately headed an expedition from Dublin to Ulster, where he took Down patrick, the capital of the northern kingdom. De Courci ultimately established his power over that part of Ulster comprised in the modern counties of Antrim and Down. After the accession of Richard I., de Courci in conjunction with William de Lacy seems to have offended the king by his proceedings in Ireland. De Lacy made his peace with Richard, while de Courci defied him; and the subsequent history of the latter consisted mainly in the vicissi tudes of a lasting feud with the de Lacys. In i 204 Hugh de Lacy took de Courci prisoner, but after his release he again appeared in arms on hearing that Hugh de Lacy had obtained a grant of Ulster with the title of earl; and in alliance with the king of Man he ravaged the territory of Down. He was routed by Walter de Lacy, and disappeared from the scene till 1207, when he obtained per mission to return to England. In i 210 he was in favour with King John, from whom he received a pension, and whom he accom panied to Ireland. Both de Courci and his wife Affreca were bene factors of the Church, and founded several abbeys and priories in Ulster.