His Holiness Karekin II, was born on 21st August 1951 in the village of Voskehat near Etchmiadzin. He entered the Theological Seminary of Holy Etchmiadzin in 1965, graduating with honours in 1971. For a year after his graduation, he taught New Testament at the Theological Seminary. In 1970 he was ordained a deacon, and in 1972 a celibate priest.

Shortly thereafter, HH Vasken I Catholicos of All Armenians sent the new priest to Vienna to study theology. In 1975, Fr. Nersissian moved to Germany, where he studied and graduated from Bonn University, while serving as pastor to the local Armenian Community. Following a brief return to Armenia, he enrolled to postgraduate studies at the Russian Orthodox Academy in Zagorsk, Russia, from which he graduated in 1979.

In March 1980 he entered the service of the Armenian Pontifical Diocese, the Armenian Church’s most populous diocesan jurisdiction, which incorporates the capital Yerevan and the vicinity of the Mother See of Holy Etchmiadzin. He was appointed the head of that Diocese in June 1983 and soon was elevated to the rank of bishop on 23rd October of the same year, by His Holiness Vasken I. In November 1992 he was granted the title of Archbishop.

In November 1998 Archbishop Karekin Nersissian was appointed as Pontifical Vicar by His Holiness Karekin I and served in this capacity until the death of the late Catholicos.

On 27th October 1999, the National-Ecclesiastical Assembly held in Holy Etchmiadzin, elected Archbishop Karekin Nersissian Catholicos who thus became Karekin II, Supreme Patriarch and Catholicos of All Armenians. The consecration and enthronement of the Catholicos took place on 4th November 1999.