Abstract
Armenia belongs to the territories where Christianity is historically documented since shortly after the death of Jesus Christ. The Armenian Church was even the very first that achieved state recognition, because the Armenian king Tiridates III. proclaimed Christianity as the official religion in his country as early as 301.
Interchurch break in communication between Armenia, Rome and Constantinople came after the Council of Chalcedon (451), where the Armenian Church did not participate. For fear of falling into heresy, subsequently the Armenian Church did not adopt its Christological conclusions and since the 6th century it remained definitively without any communion with both centers of Christianity.
Soon after invasion of Muslims into the Armenian kingdom, most of population moved farther south to the Mediterranean Sea in Cilicia, where the main church leader called Catholicos also resettled. When the Arabs occupied also this territory, part of Armenians (with their Catholicos) returned to their original homeland, while the remainder stayed at the new territory, and the second Catholicosate of Cilicia was established in the Church.
The first attempts to reactivate unity with Rome emerged from the second Catholicos. In the 17th century, these efforts reached a concrete form in the monk Mchitar of Sebaste and in the archbishop Ardzivian Abraham, who officially applied for admission into the Catholic Church.
Armenians in both areas (the original one became a part of Russia, then the Soviet Union, the new one became a part of the Turkish Ottoman empire) suffered from persecution, which culminated in the genocide at the turn 20th century, during which about 1.5 million Armenian Christians died, both members of the Armenian Apostolic Church and the Armenian Catholic Church