Patriarch Sergius (Russian: Патриарх Сергий; born Ivan Nikolayevich Stragorodsky, Иван Николаевич Страгородский; January 23 [O.S.

Starting in 1927, he pursued a policy of unconditional loyalty to the Soviet regime,[1] which led to significant criticism of him and the separation of some lay people and clerics.

On 12 April 1925, 5 days after the death of Tikhon, one of the candidates, Metropolitan Peter of Krutitsy, was elected as the patriarchal locum tenens (Местоблюститель Патриаршего Престола).

[3] Seeking to convince Soviet authorities to stop the campaign of terror and persecution against the Church, Sergius, acting patriarchal locum tenens, tried to look for ways of peaceful reconciliation with the government.

On July 29, 1927, together with a members of the Synod he issued his famous declaration [ru]: an encyclical letter where he professed the absolute loyalty of the Russian Orthodox Church to the Soviet Union and to its government's interests.

[4][5]This declaration sparked an immediate controversy among the Russian Eastern Orthodox, many of whom (including many notable and respected bishops in prisons and exile) broke communion with Sergius.

Only after the German invasion of the Soviet Union in 1941 did Joseph Stalin finally start to scale back the anti-religious campaign, needing the moral support of the Church during the war.

In the early hours of September 5, 1943, Stalin met with the three chief hierarchs of the Russian Orthodox Church and promised some concessions to religion in exchange for their loyalty and assistance.

Among the concessions were the permission to open the Moscow Theological Seminary and Academy, the release of imprisoned clerics, the return of some church property, including the famous Trinity Lavra of St. Sergius.