The Glen of Imaal is named from the Uí Máil, who dominated the kingship of Leinster in the 7th century. They were ousted by the Uí Dúnlainge from the lowlands of what would be County Kildare, and from that time until the early 13th century were located along the western foothills of the Wicklow mountains. The valley appears to have been a center of their power. By the 14th century, O'Tuathail (O'Toole) (of the Uí Dunlainge) had taken the lordship of the Uí Máil, having in their turn been expelled from south Kildare by Norman incomers.