The name of Prince Peter Boryatinsky is often encountered in documents of the sixteenth century. Thus, he was among those sent off to wage war against the Swedish king at the river Sestra. In 1576, he was named voevod at Tula. In 1580, Boryatinsky, having been appointed voevod at Kholm, was captured by the Lithuanians under a siege headed by Panin. Upon his release from captivity under Boris Godinov, Boryatinsky returned home in disgrace.
In 1591 he was named voevod at Tiumen, but after several years he left the world, settled at Briansk and received monastic tonsure with the name Polycarp. From his means the monk built a monastery of the Transfiguration of the Lord and established in it a Rule of strict ascetical life. Saint Polycarp was the first Superior of this monastery. He died and was buried there in 1620 or 1621.