Origins of the Armenian Apostolic Church

The Armenian Apostolic Church (sometimes called the Armenian Orthodox Church or the Gregorian Church) is the world's oldest national church and one of the most ancient Christian communities.
It is headed by a Catholicos (the plural is Catholicoi). The Armenian Apostolic Church should not be confused, however, with the Armenian Catholic Church whose patriarch (Governing bishop of the Armenian Rite) is Nerses Bedros XIX, which is an Eastern Catholic church in communion with the Holy See in Rome. At present, the Catholicos of All Armenians is his Holiness Karekin II (sometimes spelled as Garegin), who resides in the city of Echmiadzin, west of Yerevan.
A second Catholicos, His Holiness Aram I Catholicos of Cilicia, who resides in Antilyas in Lebanon, leads churches belonging to the Holy See of Cilicia. The division stems from frequent relocations of the Church headquarters under Ottoman Rule and was further reinforced during the period in which Armenia was part of the Soviet Union. However, the Catholicos of All Armenians claims theoretical sovereignty over the Catholicos of Cilicia.
The Armenian Apostolic Church is one of a few apostolic churches in the world to have a democratic system; the people decide if they want to keep priests in their churches and may ask for different ones, as do some other ecclesiastical constitutions, such as Presbyterians.