Early Life and Formation
He was born Ivan Uskokovic in 1889. Sources place his birth in or near Podgorica, Montenegro; one diocesan account specifies the village of Kornet in Ljesani County and names his parents as Petar and Jela Uskokovic. He pursued his early studies in Montenegro and Serbia before entering the Studenica Monastery, where he received the monastic name Mardarije.
By tradition he took monastic vows in 1906 with the blessing of Bishop Sava (Barac) of Zica and was ordained a deacon. He then spent his formative years in Russia, studying at the seminary in Kishinev and graduating from the Theological Academy in Saint Petersburg in 1916. During his time as a student he is said to have traveled to deliver lectures to Slav prisoners in Siberia, Turkestan, and Bukhara.