St. Bruno of Cologne, after brilliant studies at Paris, was made a canon of Rheims cathedral. Feeling himself called to a life of retirement and penance he betook himself with six companions to a solitude called the Chartreuse and there laid the foundations of the Carthusian Order. In the end he left Chartreuse for a most desolate place where he passed the rest of his life in a cave. He died October 6, 1101.
(Source: The New Roman Missal, Rev. F. X. Lasance)