Zareh I was born in 1915, in Marash, Ottoman Empire as Simon Payaslian.
Escaping the events of the Armenian genocide, his family moved to Syria, residing in the city of Hama, then in Aleppo.
Later, he became a graduate of the Antelias Seminary of the Armenian Catholicosate of the Great House of Cilicia.
[1] On 20 February 1956, Zareh Payaslian was elected as Catholicos of the Holy See of Cilicia, during very acrimonious times between various Armenian political factions that had left the position vacant for around 4 years since the death of Catholicos Karekin I in 1952.
After his election, Zareh I tried to restore some harmony between various Armenian factions, particularly after the inter-Armenian strife in Lebanon in 1958.