The so-called ‘Sunday Letter’ (otherwise entitled the ‘Heavenly Letter’, the Carta Dominica or the ‘Lettre du Christ tombée du ciel’) is extant in Latin and many vernacular languages and has already attracted a considerable explicatory literature. As is well known, the ‘Sunday Letter’ purports to be a letter from Christ himself, written variously in his own blood, with a golden rod or by an angel. It falls on to one of the principal shrines of Christendom (frequently Rome, Jerusalem or Bethlehem) and passes into the hands of the clergy. The letter urges strict enforcement of the observance of Sunday, accompanied by dire threats for those who fail to comply. ‘Sunday Lists’ (also known as the ‘Benedictions of Sunday’ or the dignatio Diei dominici), sometimes lengthy, are inserted within some of the extant examples of the ‘Letter’. These enumerate notable scriptural events which occurred, or are said to have occurred, on Sunday, in order to strengthen reasons for veneration of the day. Recent publication of individual, and isolated, ‘Sunday Lists’ from early Hiberno-Latin manuscripts has suggested that a survey of available and new material and a reconsideration of the relationship between the ‘Sunday Lists’ and the ‘Sunday Letter’ would be useful.