"The monks of St. Dogmael's Abbey in Pembrokeshire had much in common with the Cistercians who sought to re-introduce the purity of the original rule of St. Benedict. It was a daughter house of the French abbey of Tiron, lying between Chartres and Le Mans, that had its inspiration from the Benedictine St. Bernard of Abbeville. The 'Congregation' of Tiron, unhappy at the extent to which the observance of the rule had fallen, began to live apart. Although never finally forsaking the allegiance to St. Benedict, they distinguished themselves by changing the black habit for grey. The monastery of St. Dogmaels or Cemais was founded about 1115 by Robert FitzMartin, Lord of Cemais on the site where an older Welsh monastic community, a clas, had once been. In the latter half of the thirteenth century, an infirmary was added as a separate building, about 45 feet to the east of the abbey. When the abbey was suppressed in 1536 it had only an abbot and eight monks."
From: Cule, John. Some Early Hospitals in Wales and the Border. National Library of Wales journal. 1977, Winter Volume XX/2.