Saint Aelred of Rievaulx (1110–1167), also known as Ailred or Ælred, was an English Cistercian monk who served as Abbot of Rievaulx from 1147 until his death. Born in Hexham, Northumbria, he spent his youth at the court of King David I of Scotland before entering the Cistercian abbey of Rievaulx in 1134. Under his administration the abbey grew to some 140 monks and 500 conversi. Aelred is renowned for his treatise De spirituali amicitia (“On Spiritual Friendship”), which designates Christ as the source and ultimate impetus of spiritual friendship, and for his Speculum caritatis (“The Mirror of Charity”). He is venerated as a saint, commemorated on 12 January in the Roman Martyrology and the calendars of the Church of England and the Episcopal Church.