The Cistercian abbey of Tintern is one of the greatest monastic ruins of Wales. It was only the second Cistercian foundation in Britain, and the first in Wales, and was founded on 9 May 1131 by Walter de Clare, lord of Chepstow. It soon prospered, thanks to endowments of land in Gwent and Gloucestershire, and buildings were added and updated in every century until its dissolution in 1536. Its position well away from the Welsh heartland meant that, unlike Margam, Neath and Llanthony, it suffered little in the periodic Welsh uprisings of the medieval period..