[1] His duties required him to travel extensively, and during this time, he developed a close acquaintance with the future Patriarchs Tikhon (Bellavin) and Sergius (Stragorodsky).

When the Education Committee was closed down in 1918, in the aftermath of the Bolshevik Russian Revolution, Polyansky worked in the apparatus of the All-Russian Council of 1917–1918 in Moscow.

After the request was made, he was reported as saying: "If I refuse, I will be a traitor of the Church; but I am aware that by accepting this offer, I am signing my own death sentence.

"[2] Peter was tonsured a monk by Metropolitan Sergius (Stragorodsky) and quickly advanced through the clerical ranks to be consecrated as Bishop of Podolsk by Patriarch Tikhon on October 8, 1920.

Since Peter was the only candidate who was not in prison or exile at the time, on April 12, 1925 (the day of Tikhon's funeral), he was confirmed as the Patriarchal locum tenens.

While Peter agreed with the need for Orthodox Soviet citizens to be politically loyal, he regarded any reconciliation with the Living Church to be possible only on the condition of the schismatics' repentance.

The latter followed on December 10, 1925, and his duties passed onto Metropolitan Sergius (Stragorodsky) who became Deputy locum tenens, with Peter as a nominal head of the Church.

In July 1936, his confinement was extended to three more years, while Metropolitan Sergius was given a false report of Peter's death and therefore assumed the full leadership of the Russian Orthodox Church with the consent of their supporters, but only as a locum tenens, because authority doesn't allow him to convene a council for the purpose of electing the patriarch.