Bishop Irinej (Miroslav Gavrilović) was born on August 28th 1930 in the village Vidovi near Čačak, where he finished the high school. He finished the Prizren Seminary in 1951, graduating subsequently at the Theological Faculty in Belgrade. In 1959, he took the monastic order in the Rakovica Monastery in the vicinity of Belgrade. Patriarch German ordained him to the ranks of hierodeacon and caloyer on October 24th and 27th 1959, respectively. In the period from 1959 to 1968 he was a teacher of the Prizren Seminary. Having received the scholarship of the World Union of Churches, he enrolled the theological studies in Greece in the academic year of 1962/1963. Upon graduating, he was appointed director of the Monastic School in Ostrog. He was the professor and rector of the Prizren Seminary from 1971 to 1974. In May 1974, he was elected vicarial bishop of His Holiness Serbian Patriarch German and awarded the title of the bishop of Moravica. At the session of the Holy Synod, held on May 21-28th 1975, he was ordained bishop of the Niš Eparchy. Bishop Irinej was enthroned to the seat of the Niš Eparchy in the Cathedral of Niš, on June 15th 1975.

Many churches have been restored or rebuilt since bishop Irinej came to the head of the Niš Eparchy.