For a long time, the Ofen Ecclesiastical Mission was a place of spiritual care and consolation for Russian people who found themselves in Hungary.

On November 15, 1949, Patriarch Alexius I approved the Regulation (Charter) on the management of parishes that are part of the Hungarian Deanery, as well as a power of attorney to resolve and implement issues of his current life.

On March 21, 1996, by the decision of the Holy Synod oif the ROC, the Hungarian Deanery was removed from the direct subordination of the DECR, and its management was entrusted to Archbishop Theophan (Galinsky) of Berlin and Germany.

These actions took place with the knowledge and with the active participation of Metropolitan Michael (Staikos) of Austria, the governor of the Hungarian Exarchate.

On December 29, 1999, by the decision of the Holy Synod, the archpastoral care of the parishes of the Hungarian Deanery was entrusted to Bishop Paul (Ponomaryov), appointed to the Diocese of Vienna and Austria.

On April 19, 2000, by the decision of the Holy Synod of the ROC, the parishes of the Hungarian deanery were transformed into an independent diocese, with Archbishop Paul (Ponomaryov) received the title of "Vienna and Budapest".

Not satisfied with the seizure of three churches, Metropolitan Michael (Staikos) of Austria tried to alienate the Assumption Cathedral in Budapest from the diocese.

Divine services of the new parish were celebrated and are held in the Cathedral of the Assumption of the Blessed Virgin Mary on Petőfi Square, 2, in Church Slavonic and according to the Julian Calendar[4] On May 7, 2003, Archbishop Paul (Ponomaryov) was transferred to the Diocese of Ryazan, and Bishop Hilarion (Alfeyev) of Vienna and Austria who also was appointed locum tenens of the Diocese of Budapest.