Christianity in the 11th century is marked primarily by the Great Schism of the Church, which formally divided the State church of the Roman Empire into Eastern (Greek) and Western (Latin) branches.
In 1054, following the death of the Patriarch of Rome Leo IX, papal legates (representatives of the Pope) from Rome traveled to Constantinople to deny Michael Cerularius, the reigning Patriarch of Constantinople, the title of Ecumenical Patriarch and to insist that he recognize the Church of Rome's claim to be the head and mother of the churches. Cerularius refused, resulting in the leader of the contingent from Rome excommunicating Cerularius and the legates in turn being excommunicated by Constantinople. Though this event, in and of itself, was relatively insignificant (and the authority of the legates in their actions was dubious) it ultimately marked the end of any pretense of a union between the eastern and western branches of the Church. Though efforts were made at reconciliation at various times, they remained divided, either claiming to be the true Christian Church.
Investiture Controversy
The first major phase of the struggle between Church and state in medieval Europe was marked by the Investiture Controversy between emperor and Pope over the right to make church appointments. The Papacy were the initial victors, but as Italians divided between Guelphs and Ghibellines in factions that were often passed down through families or states until the end of the Middle Ages, the dispute gradually weakened the Papacy, not least by drawing it into politics. In 1059 the Church attempted to control, or exact a price for, most marriages among the great by prohibiting marriages involving consanguinity (blood kin) and affinity (kin by marriage) to the seventh degree of relationship. Under these rules, almost all great marriages required a dispensation. The rules were relaxed to the fourth degree in 1215.
The Investiture Controversy, or Lay investiture controversy, was the most significant conflict between secular and religious powers in medieval Europe. It began as a dispute in the 11th century between the Holy Roman Emperor Henry IV, and Pope Gregory VII concerning who would appoint bishops (investiture). The end of lay investiture threatened to undercut the power of the empire and the ambitions of noblemen for the benefit of Church reform.
Bishops collected revenues from estates attached to their bishopric. Noblemen who held lands hereditarily passed those lands on within their family. However, because bishops had no legitimate children, when a bishop died it was the king's right to appoint a successor. So, while a king had little recourse in preventing noblemen from acquiring powerful domains via inheritance and dynastic marriages, a king could keep careful control of lands under the domain of his bishops. Kings would bestow bishoprics to members of noble families whose friendship he wished to secure. Furthermore, if a king left a bishopric vacant, then he collected the estates' revenues until a bishop was appointed, when in theory he was to repay the earnings. The infrequence of this repayment was an obvious source of dispute. The Church wanted to end this lay investiture because of the potential corruption, not only from vacant sees but also from other practices such as simony.
Pope Gregory VII issued the Dictatus Papae, which declared that the Pope alone could appoint or depose bishops or translate them to other sees. Henry IV's rejection of the decree lead to his excommunication and a ducal revolt; eventually Henry received absolution after dramatic public penance barefoot in Alpine snow and cloaked in a hairshirt, though the revolt and conflict of investiture continued. Likewise, a similar controversy occurred in England between King Henry I and St. Anselm, Archbishop of Canterbury, over investiture and ecclesiastical revenues collected by the king during an episcopal vacancy. The English dispute was resolved by the Concordat of London in 1107, where the king renounced his claim to invest bishops but continued to require an oath of fealty from them upon their election. This was a partial model for the Concordat of Worms (Pactum Calixtinum), which resolved the imperial investiture controversy with a compromise that allowed secular authorities some measure of control but granted the selection of bishops to their cathedral canons. As a symbol of the compromise, lay authorities invested bishops with their secular authority symbolised by the lance, and ecclesiastical authorities invested bishops with their spiritual authority symbolised by the ring and the staff.
Byzantine conquest of Bulgaria
Emperor Basil II Porphyrogenitus sought to restore former territories of the Byzantine Empire. By 1000, Basil II had fought off his own nobility and defeated the Islamic threat from the east, and so led another invasion of Bulgaria. Bulgaria had been partly subjugated by John I Tzimiskes after the invasion of Svyatoslav I of Kiev but parts of the country had remained outside Byzantine control under the leadership of Samuel and his brothers.
This time instead of marching into the middle of the country, he annexed it bit by bit. Eventually, after denying Bulgaria of about a third of its land, the Bulgarians risked everything in one battle in 1014. The Battle of Kleidion was a disaster for the Bulgarians and the Byzantine army captured 15,000 prisoners; 99 out of every 100 was blinded and the 100th was spared one eye to guide the rest back to their homes. The Bulgarians resisted until 1018 when they finally submitted to Basil II's rule.
Following his final subjugation of the Bulgarian state in 1018, Basil II, to underscore the Byzantine victory, established the Archbishopric of Ohrid by downgrading the Bulgarian patriarchate to the rank of the archbishopric. The now archbishopric remained an autocephalous church, separate from the Patriarchate of Constantinople. However, while the archbishopric was completely independent in any other aspect, its primate was selected by the emperor from a list of three candidates submitted by the local church synod. In three sigillia issued in 1020 Basil II gave extensive privileges to the new see.
Although the first appointed archbishop (John of Debar) was a Bulgarian, his successors, as well as the whole higher clergy, were selected from Byzantines. The monks and the ordinary priests continued to be predominantly Bulgarian. To a large extent the archbishopric preserved its national character, upheld the Slavonic liturgy, and continued its contribution to the development of Bulgarian literature.
Theology
Western theology before Scholasticism With the division and decline of the Carolingian Empire, notable theological activity was preserved in some of the Cathedral schools that had begun to rise to prominence under it – for instance at Auxerre in the 9th century or Chartres in the 11th. Intellectual influences from the Arabic world (including works of classical authors preserved by Islamic scholars) percolated into the Christian West via Spain, influencing such theologians as Gerbert of Aurillac, who went on to become Pope Sylvester II and mentor to Otto III. (Otto was the fourth ruler of the Germanic Ottonian Holy Roman Empire, successor to the Carolingian Empire). With hindsight, one might say that a new note was struck when a controversy about the meaning of the eucharist blew up around Berengar of Tours in the 11th century: hints of a new confidence in the intellectual investigation of the faith that perhaps foreshadowed the explosion of theological argument that was to take place in the 12th century.
Notable authors include: Fulbert of Chartres (died 1028) Berengar of Tours (c.999-1088) Lanfranc (died 1089)
Monasticism One of the major developments in monasticism during the 11th century was the height of the Cluniac reforms, which centred upon Cluny Abbey in Burgundy, which controlled a large centralised order with over two hundred monasteries throughout Western Christendom. Cluny championed a revived Papacy during this century and encouraged stricter monastic discipline with a return to the principles of the Benedictine Rule. Cluny Abbey promoted art and literature, and the liturgy at the Romanesque abbey church was an ornate formal affair dedicated to glorifying God. Together with the revived Papacy, Cluny worked for greater devotion among men in the Church. Towards the end of the 12th century, the wealth and power of Cluny was criticised by many monastics in the Church, especially those that broke from the Cluniac order to form the Cistercians, who devoted themselves with much greater rigor to manual labour and severe austerity.Lawrence, C. H. Medieval Monasticism. 3rd ed. Harlow: Pearson Education, 2001.
Spread of Christianity
Poland The spread of Christianity was reversed temporarily in Poland, as the pagan reaction in Poland saw many churches and monasteries burned, and priests killed.
Scandinavia
Scandinavia was the last part of Germanic Europe to convert and most resistant. From the High Middle Ages, the territories of Northern Europe were gradually converted to Christianity under German leadership. German and Scandinavian noblemen extended their power to Finnic, Samic, Baltic and some Slavic peoples. Migrations of peoples, although not strictly part of the 'Migration Age', continued beyond 1000, marked by Viking, Magyar, Turkic and Mongol invasions, also had significant effects, especially in eastern Europe.
Goths Many Goths converted to Christianity as individuals outside the Roman Empire. Most members of other tribes converted Christian when their respective tribes settled within the empire, and most Franks and Anglo-Saxons converted a few generations later. During the later centuries following the Fall of Rome, as the Roman Church gradually split between the dioceses loyal to the Patriarch of Rome in the West and those loyal to the other Patriarchs in the East, most of the Germanic peoples (excepting the Crimean Goths and a few other eastern groups) gradually became strongly allied with the Western Church, particularly as a result of the reign of Charlemagne.
Georgia In 1010, the church in the unified Kingdom of Georgia became autocephalous (self-governing), and its catholicos (Melchizedek I) was elevated to the rank of patriarch and obtained the official title of Catholicos-Patriarch of All Georgia.
East-West Schism
The East-West Schism, or Great Schism, separated the Church into Western (Latin) and Eastern (Greek) branches, i.e., Western Catholicism and Eastern Orthodoxy. It was the first major division since certain groups in the East rejected the decrees of the Council of Chalcedon (see Oriental Orthodoxy) and was far more significant. Relations between East and West had long been embittered by political and ecclesiastical differences and theological disputes.
There were doctrinal issues like the filioque clause and the authority of the Pope involved in the split, but these were exacerbated by cultural and linguistic differences between Latins and Greeks. Prior to that, the Eastern and Western halves of the Church had frequently been in conflict, particularly during the periods of iconoclasm and the Photian schism. The Orthodox East perceived the Papacy as taking on monarch type characteristics that were not in line with the church's historical tradition.Kallistos Ware, The Orthodox Church London, St. Vladimir's Seminary Press 1995