Ecumenical Council of Constantinople condemns Photius. This council and succeeding general councils are denied by the Eastern Orthodox Churches. 910: Great Benedictine monastery of Cluny rejuvenates western monasticism. Monasteries spread throughout the isolated regions of Western Europe. 962: King Otto the Great of Germany (East Francia) was crowned Holy Roman Emperor by Pope John XII in St. Peter's Basilica. 966: Mieszko I of Poland converts to Catholicism, beginning the Baptism of Poland. 988: Vladimir I the Great is baptized; becomes the first Christian Grand Duke of Kiev. 1000/1001 Stephen I of Hungary becomes King of Hungary, He would later convert to Roman Catholicism becoming the Founder of the Catholic Church in Hungary. Second millennium 1001-1453 1012: Burchard of Worms completes his twenty-volume Decretum of Canon law. April 1033/1034: Saint Anselm of Canterbury is born July 16, 1054: Liturgical, linguistic, and political divisions cause a permanent split between the Eastern and Western Churches, known as the East–West Schism or the Great Schism. The three legates, Humbert of Mourmoutiers, Frederick of Lorraine, and Peter, Archbishop of Amalfi, entered the Cathedral of the Hagia Sophia during Mass on a Saturday afternoon and placed a papal Bull of Excommunication on the altar against the Patriarch Michael I Cerularius. The legates left for Rome two days later, leaving behind a city near riots. November 27, 1095: Pope Urban II preaches to defend the eastern Christians, and pilgrims to the Holy Land, at the Council of Clermont. 1098: Foundation of the reforming monastery of Cîteaux, leads to the growth of the Cistercian order. 1099: Retaking of Jerusalem by the 1st Crusade, followed by a massacre of the remaining non-Christian inhabitants, and the establishment of the Crusader kingdoms; Latin bishops are appointed to dioceses still largely populated by the Orthodox. 1123: First Ecumenical Lateran Council. Among other internal issues it tackled, Canon 3 of the council (in response to widespread abuse among the clergy) forbade priests, deacons, and sub-deacons to associate with concubines or women in general other than with female family members. 1139: Second Ecumenical Lateran Council, promulgated a rule forbidding diocesan or secular priests to marry. 1144: The Saint Denis Basilica of Abbot Suger is the first major building in the style of Gothic architecture. 1150: Publication of Decretum Gratiani furnishing a guide to canon law for centuries, until 1918. 1179: Third Ecumenical Lateran Council. 1182: The Maronite Church reaffirms its unbroken communion with the