In 1945, Soviet authorities arrested, deported, and sentenced to forced-labor camps in Siberia and elsewhere the church's metropolitan Yosyf Slipyi and nine other Greek Catholic bishops, as well as hundreds of clergy and leading lay activists. In Lviv alone, 800 priests were imprisoned. All the above-mentioned bishops and significant numbers of clergymen died in prisons, concentration camps, internal exile, or soon after their release during the post-Stalin thaw. The exception was metropolitan Yosyf Slipyi who, after 18 years of imprisonment and persecution, was released thanks to the intervention of Pope John XXIII, Slipyi took refuge in Rome, where he received the title of Major Archbishop of Lviv, and became a cardinal in 1965.