Christianity in the 11th century

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, each claiming to be the true Christian Church.

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.

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