CASAMARI, CISTERCIAN CONGREGATION of. – Cistercian abbey in the diocese of Veroli, in a locality called Cerate, traditionally the birthplace of Gaius Marius, hence the name Casa Marii. Its origin dates back to 1005, through the work of four priests from Veroli who had withdrawn there to a life of penance. After about thirty years of communal life, they received the Benedictine habit at the nearby monastery of Sora, founded by the holy abbot Domenico. They introduced a regular monastic life at C. and, around the church dedicated to SS. Giovanni and Paolo, suitably arranged the monastery, of which Benedetto, one of the four, was elected abbot. He enlarged the building and increased the resources of the nascent abbey; his successors built churches in various localities and increased its possessions. Abbot Giovanni, given the freedom and progress it had by then attained, obtained from Niccolò II (1059–61) the praeceptum libertatis monasterii for himself and his successors, a privilege confirmed by several pontiffs, and finally by Honorius III in a bull dated 21 April 1222.
Meanwhile, in 1152, the fallen Benedictine monks were succeeded by Cistercians from Fossanova, on the initiative of Eugenio III. C. is the 29th daughter of Clairvaux. In 1203 Cardinal Cencio Savelli built the present monumental basilica in the Cistercian Gothic style, under the direction of Fra' Guglielmo, one of the many magistri operis to emerge from the school of Fossanova. Fourteen years later, Savelli himself, having become Pope Honorius III, consecrated II. The community grew and prospered until it became one of the principal monastic centers of central Italy. With the commendam came decline. In 1717 C. partially accepted the reform of La Trappe. On 7 December 1864, Pius IX established it as an autonomous Congregation, and on 25 February approved its constitutions. Subsequently, the abbey regained new vigor, regular life flourished there once more, and new daughter houses arose. In 1935 C. was chosen as the headquarters of the Work for the Formation of Indigenous Monasticism for Ethiopia, which lasted until
1943. In 1929 Pius XI established C. as a Congregation sui iuris with all its daughter houses. Finally, Pius XII, by a brief dated 13 July 1943, definitively approved its constitutions. Today the Congregation of C. numbers 12 houses with approximately 60 monks. C.’s exceptionally rich archive is preserved for the most part in the Vatican; the remainder has been dispersed.