Bruno of Cologne, also known as Bruno von Köln was the founder of the Carthusian Order in the 11th century. He personally founded the order's first two communities. He was a celebrated teacher at Reims, and a close advisor of his former pupil, Pope Urban II. In 1056 he was recalled to the city of Reims, where the following year he found himself head of the Cathedral school, which at the time included the direction of the schools and the oversight of all the educational establishments of the diocese. For eighteen years, from 1057 to 1075, he maintained the prestige which the Cathedral school of Reims. This biographical work is a short treatise written by one of his students, Roger of Cologne.