Patriarch of Bulgaria in the context of "Bulgarian Orthodox Church"

Religion in Bulgaria has been dominated by Christianity since its adoption as the state religion in 864. The dominant form of the religion is Eastern Orthodox Christianity within the fold of the Bulgarian Orthodox Church. During the Ottoman rule of the Balkans, Islam spread to the territories of Bulgaria, and it remains a significant minority today. The Catholic Church has roots in the country since the Middle Ages, and Protestantism arrived in the 19th century; both of them remain very small minorities. Today, a significant part of the Bulgarians are not religious, or believers who do not identify with any specific religion, and Bulgaria has been the cradle of some new religions, notably the Neo-Theosophical movement of Dunovism.

St. Alexander Nevsky Cathedral (Bulgarian: Храм-паметник "Свети Александър Невски", romanized: Hram-pametnik "Sveti Aleksandar Nevski") is a Bulgarian Orthodox cathedral in Sofia, the capital of Bulgaria. Built in the Neo-Byzantine style, it serves as the cathedral church of the Patriarch of Bulgaria and it is one of the largest Christian church buildings by volume in the world. It is one of Sofia's symbols and primary tourist attractions. St. Alexander Nevsky Cathedral in Sofia occupies an area of 3,170 square metres (34,100 sq ft) and can hold 5,000 worshipers. It is among the ten largest Eastern Orthodox church buildings. It is the largest cathedral in the Balkans. It is believed that up until the year 2000 it was the largest finished Orthodox cathedral.