Saint Bruno was born in Cologne circa 1030 AD to the family of Hartenfaust, a popular and well liked family in the town. He studied theology at Reims and was ordained a Priest in 1055 when he returned to his home in Cologne. Only a year later the Bishop Gervais recalled him to Reims where he would eventually be the headmaster of the Episcopal school there For nearly 18 years he continued to uphold the prestige of the school and earned a reputation of being an excellent philosopher and theologian.
In 1075, Saint Bruno was appointed chancellor of the Roman Catholic Archdiocese of Reims. Two years later, at the urging of Saint Bruno and the local clergy the council at Autun was convened. Bishop Manasses de Gournai had recently been elected the bishop and was known to be a violent aristocrat with no real concern or love for the church. The council suspended him which resulted in Manasses having his followers ransack the homes of his accusers. Pope Bruno found his home completely ransacked any possessions stolen. He avoided returning to Reims until 1080 when Manasses took refuge with Henry IV after a violent riot in the city.
The clergy attempted to persuade Saint Bruno of becoming the next bishop, but he instead followed a vow he had previously made to renounce all secular concerns. Bishop Hugh of Chateauneuf provided Saint Bruno and his companions a small plot of land in an mountainous and uninhabited spot named Chartreuse (close to Grenoble). It was here he and his companions lived an isolated life in poverty and full occupied with prayer and study. The monks ate alone, only eating together on feast days. Any time not spent in prayer or study was spent copying manuscripts.
One of Saint Bruno's pupils, Eudes of Chatillon had recently become pope (Pope Urban II in 1088) and in the struggle against the Antipope Clement III and Henry IV called Saint Bruno to Rome to fill the need of devoted and competent allies. Saint Bruno acknowledged this call and came to Rome where he worked as a advisor , keeping away from the public eye and partisan rivalries. Saint Bruno was asked to become Archbishop of Reggio Calabria, but refused, begging instead to be allowed to return to his brothers.
Saint Bruno was allowed to take some followers and form a new retreat in 1091 in a small forested high valley in the Diocese of Squillace. Roger I of Sicily granted the group land and became close friends with Saint Bruno.
Saint Bruno died on October 6th, 1101 near Serra San Bruno. Because the Carthusian Order maintains a strict observance of humility, Saint Bruno was never formally canonized. Pope Gregory XV added his memorial to the General Roman Calendar in 1623.