In 1199, Henry served as mediator of a dispute between Guy II, Count of Auvergne and his brother Robert of Auvergne, Bishop of Clermont, that resulted in a state of civil war in Auvergne. The mediation failed and Guy was excommunicated. Following Henry's death, Henry’s brother Eudes, Bishop of Paris, was called upon to nominate a successor, and finding consensus impossible among the factions, he prayed for divine guidance and drew lots, selecting (future Saint) William of Donjeon, who was duly elected.[2]
Alain de Lille would dedicate his Liber poenitenitalis to Henry de Sully.[3]
Baring-Gould, Sabine (1877). The Lives of the Saints (3rd ed.). John Hodges.
Devailly, Guy (1973). Le Berry du X siecle au milieu du XIII (in French). Mouton & Co.
Krochalis, Jeanne E. (1995). "Alain de Lille". In Kibler, William W.; Zinn, Grover A. (eds.). Medieval France: An Encyclopedia. Garland Publishing, Ltd. pp. 17–18.