Old-Aquileia

The Patriarchate of Old-Aquileia were claimants to the title of Patriarch of Aquileia.

They split from the Patriarch of Aquileia in Grado when the patriarch reconciled with Rome in the Schism of the Three Chapters.

The bishops under the patriarch of Aquileia had split with Rome when they refused to condemn theologians who had been condemned by the rest of the Church. After the Lombard invasion of Northern Italy they had fled to the island of Grado, then under control of the Byzantines, although for years they maintained the schism. In 606 the newly elected bishop reconciled with Rome.

Many mainland bishops, whose dioceses were under Lombard control were unhappy with the reconciliation. These dissidents fled to mainland Aquileia and under Lombard protection elected a John as a rival patriarch who maintained the schism. There were now two patriarchates in northern Italy, Aquileia in Grado and Old-Aquileia.

Thus, the schism deepened now along political Lombard-Roman lines.

The Irish missionary Columbanus, who was ministering to the Lombards in Bobbio was involved in the first attempt to resolve this division through mediation between 612 and 615. He was persuaded by Agilulf, King of the Lombards, to address a letter on the schism to Boniface IV. He tells the pope that he is suspect of heresy for accepting the Fifth Ecumenical Council (the Second Council of Constantinople in 553), and exhorts him to summon a council and prove his orthodoxy.

Edward Gibbon claims that Pope Honorius I reconciled the Patriarch to Rome in 638, although this did not last.

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Wikipedia