The future Metropolitan Petar was the son of a nobleman (vojvoda) and priest Bogdan Zimonjić from the region of Herzegovina.

He attended the seminary in Reljevo (in neighboring Sarajevo) between 1883 and 1887 and continued his education at the Orthodox Theological Faculty in Cernovice from 1887 until his graduation in 1893.

After World War II had broken out, Metropolitan Petar was advised to leave Bosnia and move to Serbia or Montenegro.

A Roman Catholic priest, Božidar Bralo, an adherent of the Croatian Ustaše in charge of Bosnia and Herzegovina, had a decisive role in this severe policy of forbidding the use of the Cyrillic alphabet, including the arrest of Metropolitan Petar.

However, another version states that Metropolitan Petar was taken to the Jadovno concentration camp,[6] where he was killed in a monstrous manner and his remains were thrown to an acid pit.