He was the son of the duke and priest Bogdan Zimonjić. He was born in Grahovo in 1866. He was tonsured a monk in 1895, and was elected Bishop of Zahumlje-Herzegovina in 1903. In 1920, he became Metropolitan of Dabro-Bosnia. During World War II, he bravely defended the Orthodox faith in the Serbian script before the German Gestapo. In that shameless attack, the Roman Catholic priest Božidar Bral, the Ustasha commissioner for Bosnia and Herzegovina, played a decisive role. Metropolitan Petar was arrested and imprisoned in May 1941. In prison, he was stripped of all his episcopal insignia. After severe torture, he was taken to Koprivnica, and then to Jasenovac (or Gospić). He was killed in Jasenovac and thrown into a red-hot brick kiln.

Hieromartyr Babel. Holy Prophet Moses the God-Seeker. Holy Martyrs Marcellus and Cassian.