the kingdom of armenia was the first state to adopt christianity as its official religion under the rule of king tiridates in the early 4th century. the church claims to have originated in the missions of apostles bartholomew and thaddeus in the 1st century, by tradition. the church teaches that it was first preached by two apostles of jesus, st. thaddeus and st. bartholomew. the armenian apostolic church claims to been in existence since the days of the apostles and therefore would be one of the oldest denominations of christianity. armenia was the first country to adopt christianity as its official religion, when st. gregory the illuminator converted tiridates iii (the king of armenia) and members of his court, traditionally dated to 301 (after mikayel chamchian 1784). the church teaches that st. gregory was imprisoned by tiridates in an underground pit, called khor virab, for 13 years, after which he healed the king of an incurable disease, whereupon tiridates accepted christianity.