Cardinal, canonist, born Todi, Italy; died c.1100.
A member of the Benedictine Order and a zealous ecclesiastical reformer, he was created cardinal by Gregory VII.
In 1087 he compiled and dedicated to Victor III a collection of canons (edited by Martinucci, Venice, 1869) consisting of four books: on the Roman Church, on the Roman clergy, on ecclesiastical matters, and on the liberty of the Church and the immunities of the clergy.
This work, taken partly from earlier collections, and partly from documents in the Lateran library, by which Deusdedit meant to defend the rights of the Church in keeping with the measures of Gregory VII, reveals him as one of the most important of the pre-Gratian canonists.
Under Urban II (1088-1089), he published another work which states the doctrine of the Church on the question of investiture.
The composition of the "" and the editing of Gregory's correspondence are attributed to his cardinal, who appears to have been the intimate counsellor of the famous pope.
New Catholic Dictionary