HUMBERT OF SILVA CANDIDA. - Having entered around 1015 the Benedictine monastery of Moyenmoutier in the Vosges, he distinguished himself there by a perfect knowledge of Latin and Greek. He was also a vigorous supporter of the reforms to be introduced in the Church; therefore in October 1049 Leo IX summoned him to Rome and wished to have him near himself in the circle of his most intimate advisers; in the spring of 1050 he appointed him archbishop of all Sicily and the same year created him cardinal bishop of Silva Candida. He died in Rome on 5 May 1061.
A leading part belongs to U. in the rupture between the Greek Church and the Roman Church. Fearing, in fact, their union, which the Emperor desired, Michael Cerularius, patriarch of Constantinople, made every effort to prevent it and in a letter, written under the name of Leo of Ochrida, violently attacked the Latin rites (1053). U. translated the letter, drafted the reply of Leo IX (PL 143, cols. 744-69) and wrote the treatise Adversus Graecorum calumnias (ibid., cols. 929-74).
The emperor Constantine Monomachos harbored sentiments quite different from those of Michael Cerularius, and these good dispositions prompted Leo IX to send U. and Card. Frederick of Lorraine as legates to Constantinople (1054). But the death of the Pope (19 April) was immediately exploited in such a way as to cast doubt on the authority of their mission. U. himself had to reply to a libel of the monk Nicetas Stethatos (ibid., cols. 985-1000). A theological discussion in the presence of the Emperor (24 June) turned in his favor. On 16 July, the legates, considering themselves mocked, launched the excommunication against Cerularius (the document was the work of U.: ibid., cols. 1001-1004) and departed (18 July). Overtaken at Selymbria by the Emperor's messengers, they returned; but an uprising fomented by Cerularius forced them to disappear as quickly as possible, and the excommunication launched ended by bringing about the rupture between the Roman and Greek Churches (PG 120, cols. 735-48). Having returned to the West, U. wrote (1057-58) the treatise Adversus simoniacos (PL 143, cols. 1004-1212; better in MGH, Libelli de lite imperatorum et pontificum saeculis XI et XII conscripti, I, Hannover 1891, pp. 95-253) in which he maintains the opinion that ordinations performed by simoniacal prelates are null and exalts the election of bishops made by the clergy and the people in order to put an end to the abuses of lay investiture, the principal cause of the evils that were raging.
Subsequently U. was librarian of the Roman Church and was involved in the question of Berengar of Tours (cf. the letter addressed to him, in Neues Archiv der Gesellschaft für ältere Geschichtsschunde, 7 [1882], pp. 614). The Vita S. Leonis IX papae, hitherto believed to be by Guibert (Wibertus), archdeacon of Toul, is now attributed to U. (cf. H. Tritz, Die hagiographischen Quellen zur Geschichte Papst Leo IX., in G. B. Borino, Studi Gregoriani, IV, Rome 1952, pp. 191-364; see the observations of B. de Gaiffier, in Anal. Boll., 70 [1952], pp. 423-24).