CULDEI. – Religious communities peculiar to Celtic monasticism. Their origins are little known. As a distinct institution, the Culdees belonged to the reform movement of the 8th century. “The most satisfactory hypothesis is that the Culdees were religious communities gathered around the reforming leaders... and that the method they followed was to combine the austerity of the life of recluses or anchorites with well-organized communal life and strict, rigorous oversight by a spiritual superior” (Kennedy).
Their name, considered by some to be a corruption of the Latin *cultores Dei*, derives from the Celtic (Irish *Céli Dé*, Scottish *Kéli Dei*) and means “servants of God.” Though the word is ancient, as a specific term for a category of monks it is found only from the 8th century onward, in forms such as Coldeus, Caldeus, Keledeus (English *Culdee*).
The best-known apostle of this reform is Máel-Ruain (d. 792), founder of the monastery of Tamlachta (now Tallaght, near Dublin), the principal center of the movement. Among his notable disciples were Máel-Dithruib and, above all, Óengus (or Aengus), called “the Culdee.” From Tamlachta come three famous documents: the Martyrology of Óengus, the Martyrology of Tallaght, and the Stowe Missal.
A monastic rule is attributed to St. Máel-Ruain, edited and translated into English by W. Reeves. It should be noted that all known Irish rules, though bearing the names of ancient saints, in the form in which they have come down to us belong to this period of the 8th–9th centuries.
At Tallaght the Culdees formed the entire monastic community, whereas elsewhere, as at Ros-ere, they constituted a distinct community situated near the old monastic church; in other places, such as Armagh, they formed a special group, almost a community of “strict observance” in contrast to the older, larger, and more lax organization.
Their customs are partly known from three surviving Irish texts: 1) the aforementioned Rule of St. Máel-Ruain; 2) the *Notes on the Customs of Tallaght*, compiled partly around 840 and partly later; 3) the seventh section of the *Teachings of St. Mochuta* (d. 636), in verse (a 9th-century redaction).
Their program was: “vigils, prayer, reading, work.” Out of a spirit of mortification they excluded music. They observed a double Lent: the great one before Easter and another in summer, after Pentecost. They practiced weekly confession; the confessor was called “the friend of the soul.”
From Ireland the Culdee institution spread to Britain and Scotland (with its principal center at St. Andrews), adapting itself to local conditions. Danish invasions brought about the decline of the institution, which, however, survived until the Protestant Reformation.
At that time it was claimed that the Culdees represented the whole of Celtic monasticism, with a primitive faith “untainted by Rome.” Others, for nationalistic reasons, have argued for a Scottish rather than Irish origin.