Humbert of Silva Candida

When Humbert was 15 years old, his parents sent him to the Abbey of Moyenmoutier in Lorraine as an oblate destined for monastic life according to the Rule of St.

This exchange led to Humbert being sent to Constantinople at the head of a legatine mission with Frederick of Lorraine (later Pope Stephen IX), and Peter, Archbishop of Amalfi, to confront the Patriarch Michael Cerularius.

Finally, on 16 July 1054, during the celebration of the Divine Liturgy, Humbert placed a papal bull excommunicating the Patriarch on the high altar of the Cathedral of Hagia Sophia, unaware that Pope Leo had died a few weeks earlier in April, which some historians have suggested meant that the excommunication was invalid.

[1] This event officially crystallized the gradual estrangement of Eastern and Western Christianity that had taken place over the centuries, and is traditionally used to date the beginning of the Great Schism.

[4] In his later years, Humbert was appointed librarian of the Roman Curia by Pope Stephen IX, his former legatine companion, and he wrote the reform treatise Libri tres adversus Simoniacos ("Three Books Against the Simoniacs") (1057), which criticized those who bought or sold ecclesiastical offices (simony), including kings, for whom it had been common practice.