Benedictine monk, second abbot of Cluny
Odo of Cluny (French: "Odon") (c. 878 – 18 November 942) was the second abbot of Cluny. 
Born to a noble family, he served as a page at the court of Aquitaine. He became a canon of the Church of St. Martin in Tours, and continued his education in Paris under Remigius of Auxerre. Upon returning to Tours, Odo became disillusioned with the life of a canon and subsequently entered the Benedictine abbey at Baume, where he became superior of the abbey school.
Odo joined Abbot Berno at Cluny and when Berno died in 927, was elected his successor. While abbot, he also managed the priory at Romainmôtier. Next, he undertook the reform of Fleury Abbey. He encouraged the monks to adhere more closely to the original "Rule of Saint Benedict". In 931 the Pope authorized Odo to continue his work in the monasteries of Aquitaine. He enacted the various Cluniac Reforms of France and Italy. In 937, he went to Rome and was given Saint Paul Outside the Walls. He also sent his aides to Monte Cassino and Subiaco.
Odo initiated the practice among the monasteries following Cluny to hold an annual commemoration of all the faithful departed on the day after All Saints' Day.
He is venerated as a saint by the Catholic and Eastern Orthodox Churches. His feast day is 18 November.
There is only one contemporary biography of him, the "Vita Odonis" written by John of Salerno.
Early life.
Odo was born in about 878, the son of Abbo, feudal lord of Deols, near Le Mans and his wife Arenberga. According to the "Vita" later written by Odo's disciple John, the couple had long been childless, and one Christmas Eve, Abbo prayed to Our Lady to obtain for him the gift of a son. When the child was born, his grateful father entrusted the boy to the Church of St. Martin in Tours. Both his parents later joined monasteries. His brother Bernard also became a monk.
While yet a child, Odo was sent first to the court of Fulk the Good, Count of Anjou; later he became a page at the court of William the Pious, duke of Aquitaine, where he spent several years. Odo developed a particular devotion to Mary, under the title “Mother of Mercy", an invocation by which he would address her throughout his life.
Church of St Martin, Tours.
In the 9th and 10th centuries, the tomb of St Martin of Tours was considered one of the holiest sites in western Christendom. At age 19 Odo was tonsured as a canon of the Church of St. Martin in Tours, where he spent six years studying classic authors, the Fathers of the Church, poetry, and music. Odo would later say that the monks of the monastery of St. Martin of Tours had been spoiled by all the wealth and gifts brought by the pilgrims, and had abandoned the Rule they were required to follow. He would later tell his monks that the religious at Tours no longer attended nightly Lauds for fear of getting their fine shoes dirty. Odo's experience at Tours later led him to embrace the monastic reform movement.
In 901 he traveled to Paris where he spent four years completing a course of theological studies, including the study of philosophy under Remigius of Auxerre. Upon his return to Tours, Odo adopted a disciplined and ascetic lifestyle. One day, in reading the rule of Saint Benedict, he was confounded to see how much his life fell short of the maxims there laid down, and he determined to embrace a monastic state. The count of Anjou, his patron, refused to consent, and Odo spent almost three years in a cell, with one companion, in the practice of penance and contemplation. At length, he resolved that no impediments should any longer hinder him from consecrating himself to God in the monastic state. He resigned his canonry, and secretly repaired to the monastery of Beaume, in the diocess of Besançon, where the Abbot Berno admitted him to the habit. He brought with him only his books, which consisted of about a hundred volumes.
The Monastery at Baume.
Around 909 Odo entered Baume, which was under the direction of Abbot Berno. Berno had joined the Benedictine Order at the Abbey of St. Martin in Autun, where Hugh of Anzy le Duc had introduced stricter adherence to the Rule of Saint Benedict. Later, Berno was sent to the diocese of Besançon to restore the monastery at Baume-les-Messieurs, which had fallen into neglect.
Bishop Turpio of Limoges ordained Odo to the priesthood, which Odo was obliged to accept under obedience. However, Odo was so depressed by this, that Berno sent Odo back to the bishop to visit him. Odo and the bishop talked about the evil condition of the church and all the abuses that were occurring, Odo spoke about the book of Jeremiah, and the bishop was so impressed with his words, that he asked Odo to write it down. Odo said he could not do so without first getting permission from Berno, and the bishop then got Berno's permission, and Odo then wrote down his second book the "Collationes".
Odo became superior of the abbey school at Baume.
Cluny.
In 910 Abbot Berno left Baume to found Cluny Abbey, taking some of the monks with him. It is not clear at what point exactly Odo left Baume for Cluny. Berno had control of six monasteries when he died in 927, three of which he gave to Wido and the other three he gave to Odo. The monks of Cluny elected Odo as abbot, but he refused on grounds of unworthiness. The bishop threatened Odo with excommunication if he continued to refuse, and thus Odo accepted the office.
At Berno's death in 927 (Odo would have been almost 50), Odo became abbot of three monasteries: Deols, Massay and Cluny. Baume became the possession of Wido, who had been the leader of the monks that persecuted Odo when he was with them at Baume. Immediately following Berno's death, Wido attempted to gain control of Cluny by force, but Pope John X sent a letter to Rudolf, King of the Franks to intervene. Cluny was still not finished construction when Odo became abbot, and he continued construction efforts but he ran into financial difficulties. Odo had a strong devotion to St Martin of Tours for most of his life. He continued to pray to St Martin for all of his and the monastery's problems. One story recounts the one year, on the feast day of Martin of Tours, Odo saw an old man looking over the unfinished building. The old man then went to Odo and said that he was St Martin and that if the monks continued to persevere that he would arrange it for the money they needed to come to them. A few days later, 3000 solidi of gold was brought as a gift to Cluny.
Odo continued to uphold the Benedictine Rule at Cluny just as Berno had done. Throughout Odo's rule of Cluny, the monastery continually enjoy protection from both Popes and temporal rulers, who guaranteed the monastery's independence. Many times during Odo's reign, Cluny's property was extended as gifts of land were added to it. During his tenure as abbot, the monastic church of SS. Peter and Paul was completed.
Odo taught the monks that the blind and the lame were the porters of the gates of paradise. If a monk was ever rude or harsh to a beggar who came to the monastery gates, Odo would call the beggar back and tell him, 'When he who has served thee thus, comes himself seeking entrance from thee at the gates of paradise, repay him in like manner.' The charity of Cluny was well-known. In one year food was distributed to more than seven thousand persons in need.
Reforms of other monasteries.
After Berno's death, the first monasteries that Odo reformed were at Romainmoutier, St. Michael's Abbey at Tulle, and the Abbey of Saint-Géraud at Aurillac. He encouraged them to return to the original pattern of the Benedictine rule of prayer, manual labor, and community life under the direction of a spiritual father. It was his usual saying, that no one can be called a monk who is not a true lover, and strict observer of silence, a condition absolutely necessary for interior solitude and the commerce of a soul with God.
Odo would later relate a tale to his monks regarding two monks from Tours who chose not to wear their habits. On one occasion they were once sent out on business. One wore his habit, the other dressed like a layperson. The monk dressed as a layperson became mortally ill, and the other monk had a vision in which he saw St Benedict sitting on a throne in heaven surrounded by an army of monks. The dying monk was lying prostrate and asking for help. Benedict said that he did not recognize this monk's habit and that he must belong to a different order. Benedict then said he could do nothing as he had no jurisdiction over those of another order. The dying monk despaired, but his companion torn off his habit and wrapped it around the dying monk, and Benedict then healed the dying monk of his sickness.
In 930, he reformed Fleury Abbey. At that time Fleury held the bones of St Benedict, brought there from Monte Cassino. However, by the time of Odo, it had lost its reputation for holiness and was filled with many of the same abuses that were occurring in other places. The Viking raids had caused monks at Fleury, as in many places, to return to their villages for safety, but when they returned to the monastery again, they did not return to their old discipline and abused the Rule. Odo went to Fleury on the request of King Rudolf of the Franks. Upon arriving he found the monks armed with spears and swords and threatening to murder him. After a standoff for three days, Odo rode towards the monastery on his donkey and the monks put down their weapons.
Odo then took over leadership of it on a temporary basis and reformed it. He encountered resistance in trying to get the monks to abide by the rule against eating flesh meat. The monks would patiently wait for the supply of fish to run out in the hope that he would be forced to give them meat to eat. However, Odo consistently was always able to find a source for fish. A story from this time held that one day when Odo was present at Fleury for Benedict's feast day, Benedict appeared to a brother who had fallen asleep. Benedict told the monk that since Fleury was founded, no monk of Fleury had inherited eternal life. Benedict then asked the monk if they had enough fish, and the monk said they did not, and Benedict told him that they should fish in the marsh and not in the river. The monks then went to the marsh to fish and caught a huge catch of fish.
Authorized by a privilege of Pope John XI in 931, Odo reformed the monasteries in Aquitaine, northern France, and Italy. The privilege empowered him to unite several abbeys under his supervision and to receive at Cluny monks from abbeys not yet reformed; the greater number of the reformed monasteries, however, remained independent, and several became centres of reform. 
Cluny became the model of monasticism for over a century and transformed the role of piety in European daily life. The monastery claimed its heritage traced, through Berno and Hugh of Anzy le Duc, all the way back to St Benedict of Nursia.
In later years he also reformed many other monasteries including St Martial's and St Augustine's monasteries in Limoges, St Jean-d'Angely in Aquitaine, Jumièges Abbey in Normandy, St Peter Le Vif in Sens, and St Julian's in Tours. These monasteries, however, would go on to also reform and found other monasteries. The Cluniac observance, as established by Odo, became the model of monasticism for over a century.
In Italy.
Many monasteries in Italy were deserted, because of continual attacks by Huns and Muslims who would often deliberately seek out monasteries to plunder. The lands of monasteries were often seized by local nobles. Between 936 and 942 he visited Italy several