A name used to designate three religious orders and three sects, none of which is in existence today.
The Benedictine congregation for both monks and nuns, founded by william of vercelli, continued to grow under his successors, receiving formal papal approbation in 1197. In 1611 the congregation of monks comprised 26 larger and 19 smaller monasteries. Today, Benedictines of the Congregation of Monte Cassino hold the abbey nullius of Monte Vergine and care for its Marian shrine. The Williamite convents of Benedictine nuns at one time numbered 50, but only two or three remained at the beginning of the 18th century.
The Hermits of St. William, named for william of maleval but founded by his two companions, Albert and Renaldo, spread throughout Italy, France, Belgium, Germany, and Hungary. They were divided into two congregations when, in the 13th century, some monasteries accepted the benedictine rule and others adopted the Rule of St. augustine. Some of the latter were reincorporated into the order as Benedictines, but the motherhouse at Maleval became a house of augustinians. Most of the Benedictine monasteries that survived into the 17th century were absorbed by other branches of the Benedictine order.
The Williamite Order of Knights, which William the Pious, Duke of Aquitaine, is supposed to have founded in 887, never existed. However, an earlier Duke william of aquitaine (d. 812) had founded a Benedictine monastery for men and another for women at Gellone in Languedoc in 804. He entered the former; his two sisters, the latter. The Monastery of the Holy Cross (or of St. William) at Gellone existed until 1783.
The name of "Williamites" was sometimes given to the followers of william of saint-amour (d. 1272), the adversary of the Dominicans and Franciscans at the University of Paris.
Wilhelmine of Milan (d. 1282) and her followers, both men and women, formed a secret heretical sect, the Williamites, which was discovered and suppressed only after her death. She had claimed to be the incarnation of the Holy Spirit.
In the late 14th century, Aegidius Cantoris, a layman of Brussels, who called himself the "Savior of Men," led a heretical sect, which William of Hildernisse, a Carmelite priest, was accused of supporting. For this reason his followers were called Williamites.
Bibliography: g. henschen, Commentarius hist. de ordine eremit. S. Guilielmi, Acta Sanctorum (Paris 1863–) February 2:473–486. m. heimbucher, Die Order und Kongregationen der Katholischen Kirche, 2 v. (3 ed. Paderborn 1932–34) 1:179, 201, 302, 539. k. elm, Beiträge zur Geschichte des Wilhelmitenordens (Cologne 1962).
[m. a. habig]
"Williamites." New Catholic Encyclopedia. . Encyclopedia.com. (August 22, 2018). http://www.encyclopedia.com/religion/encyclopedias-almanacs-transcripts-and-maps/williamites
"Williamites." New Catholic Encyclopedia. . Retrieved August 22, 2018 from Encyclopedia.com: http://www.encyclopedia.com/religion/encyclopedias-almanacs-transcripts-and-maps/williamites