The Regularis Concordia was probably written by Æthelwold of Winchester as part of the reform of Benedictine monasteries in England in the late tenth century. It is based on the Rule of St. Benedict and gives guidelines for the monastic lives of monks and nuns. It contains an early example of theatre ritual or drama. An eleventh-century manuscript of the work Cotton Tiberius A. iii contains interlinear glosses in Old English. Here the official preface tells of king Edgar’s role in the Benedictine reform.