With a membership currently estimated at over 85 million members worldwide, the Anglican Communion is the third largest Christian communion in the world, after the Roman Catholic Church and the Eastern Orthodox Churches.

Some Eastern Orthodox Churches have issued statements to the effect that Anglican orders could be accepted, yet have still reordained former Anglican clergy ; other Orthodox churches have rejected Anglican orders altogether.

** April 6 ( Eastern Orthodox liturgics )

** April 15 ( Eastern Orthodox liturgics )

** April 30 ( Eastern Orthodox liturgics )

** August 22 ( Eastern Orthodox liturgics )

** August 6 ( Eastern Orthodox liturgics )

** August 9 ( Eastern Orthodox liturgics )

The Eastern Orthodox Church observes several All Souls ' Days during the year.

The Eastern Orthodox Church dedicates several days throughout the year to the dead, mostly on Saturdays, because of Jesus ' resting in the Holy Sepulchre on that day.

** August 13 ( Eastern Orthodox liturgics )

In the Eastern Orthodox and Eastern Catholic Churches, the Abbot is referred to as the Hegumen.

** August 2 ( Eastern Orthodox liturgics )

** April 1 ( Eastern Orthodox liturgics )

Arianism is defined as those teachings attributed to Arius which are in opposition to mainstream Trinitarian Christological doctrine, as determined by the first two Ecumenical Councils and currently maintained by the Roman Catholic Church, the Eastern Orthodox Churches, the Oriental Orthodox Churches, and most Reformation Protestant Churches.

** August 1 ( Eastern Orthodox liturgics )

** August 3 ( Eastern Orthodox liturgics )

** April 26 ( Eastern Orthodox liturgics )

In the Catholic Church ( both the Latin Rite and Eastern Catholic ), Eastern Orthodox, Coptic and Anglican abbeys, the mode of election, position, rights, and authority of an abbess correspond generally with those of an abbot.

** August 8 ( Eastern Orthodox liturgics )

** April 16 ( Eastern Orthodox liturgics )

The Council of Nicaea did not end the controversy, as many bishops of the Eastern provinces disputed the homoousios, the central term of the Nicene creed, as it had been used by Paul of Samosata, who had advocated a monarchianist Christology.

During this persecution many bishops were exiled to the other ends of the Empire, ( e. g., St Hilary of Poitiers to the Eastern provinces ).

In 381, at the Second Ecumenical Council in Constantinople, a group of mainly Eastern bishops assembled and accepted the Nicene Creed of 381, which was supplemented in regard to the Holy Spirit, as well as some other changes: see Comparison between Creed of 325 and Creed of 381.

Further, proponents of the necessity of the personal apostolic succession of bishops within the Church point to the universal practice of the undivided early Church ( up to AD 431 ), before being divided into the Church of the East, Oriental Orthodoxy, the Eastern Orthodox Church and the Roman Catholic Church.

Roman Catholics recognize the validity of the apostolic successions of the bishops, and therefore the rest of the clergy, of the Eastern Orthodox, Oriental Orthodox, Church of the East, and the Old Catholic Church ( Union of Utrecht only ).

Within the Catholic Church, Eastern Orthodox, Oriental Orthodox, Anglican, Old Catholic, Independent Catholic Churches, and in the Assyrian Church of the East, bishops claim apostolic succession, a direct historical lineage dating back to the original Twelve Apostles.

In the Eastern churches, latifundia entailed to a bishop's see were much less common, the state power did not collapse the way it did in the West, and thus the tendency of bishops acquiring secular power was much weaker than in the West.

Eastern Orthodox bishops, along with all other members of the clergy, are canonically forbidden to hold political office.

In Catholicism, Eastern Orthodoxy, Oriental Orthodoxy, Lutheranism, and Anglicanism, only a bishop can ordain other bishops, priests, and deacons.

Most Eastern Orthodox churches allow varying amounts of formalised laity and / or lower clergy influence on the choice of bishops.

The Catholic Church does recognise as valid ( though illicit ) ordinations done by breakaway Catholic, Old Catholic or Oriental bishops, and groups descended from them ; it also regards as both valid and licit those ordinations done by bishops of the Eastern churches, so long as those receiving the ordination conform to other canonical requirements ( for example, is an adult male ) and an orthodox rite of episcopal ordination, expressing the proper functions and sacramental status of a bishop, is used ; this has given rise to the phenomenon of episcopi vagantes ( for example, clergy of the Independent Catholic groups which claim apostolic succession, though this claim is rejected by both Orthodoxy and Catholicism ).

Eastern Rite Catholic bishops celebrating Divine Liturgy in their proper pontifical vestments.

Eastern bishops do not normally wear an episcopal ring ; the faithful kiss the bishop's hand.

Pope Paul VI also increased the number of cardinal bishops by giving that rank to patriarchs of the Eastern Catholic Churches who are made cardinals.

In 1965 Pope Paul VI decreed in his motu proprio Ad Purpuratorum Patrum that patriarchs of the Eastern Catholic Churches who were named cardinals would also be part of the episcopal order, ranked after the six cardinal bishops of the suburbicarian sees ( who had been relieved of direct responsibilities for those sees by Pope John XXIII three years earlier ).

The three Eastern patriarchs who are now cardinal bishops are the following:

Other Christian churches also laying claim to the description " Catholic " include the Eastern Orthodox Church and those churches possessing the historic episcopate ( bishops ), such as those of the Anglican Communion.

After the East-West Schism, conventionally dated to 1054, a brief reunification was agreed to between the Pope and a number of Eastern Orthodox bishops at the Council of Florence.

An Orthodox congress of Eastern Orthodox bishops met in Constantinople in 1923 under the presidency of Patriarch Meletios IV, where the bishops agreed to the Revised Julian calendar.

Both the Eastern Orthodox Church and Roman Catholic Church recognise as ecumenical the first seven councils, held from the 4th to the 9th century ; but while the Eastern Orthodox Church accepts no later council or synod as ecumenical, the Roman Catholic Church continues to hold general councils of the bishops in full communion with the Pope, reckoning them as ecumenical, and counting in all, including the seven recognized by the Eastern Orthodox Church, twenty-one to date.

In the Eastern Orthodox Church, the sixteen or so autocephalous primates are seen as collectively gathering around Christ, with other archbishops and bishops gathering around them, and so forth, in a model called " conciliar hierarchy ".