The Church of Saint George (Bulgarian: Ротонда „Свети Георги“, romanized: Rotonda "Sveti Georgi") is a Late Antique red brick rotunda in Sofia, Bulgaria.
It is considered to be the oldest preserved building in the city, built at a time when Sofia was the residence of the emperors Galerius and Constantine the Great.
Having survived the trials of time and having kept its appearance almost untouched, it is assumed that some of the most important meetings of the Council of Serdica had taken place in the church.
In the church, there were kept the holy relics of the patron saint of Bulgaria - John of Rila and, according to the legend, they were used to cure the Byzantine Emperor Manuel Comnenus.
The relics were taken by the Hungarians in 1183, during the reign of Béla III, when allied Serbs and Magyar troops invaded, destroyed and looted the city.
After a short stay in the capital Esztergom, where the Catholic bishop lost his ability to talk after an indecent act with the relics, they were returned to the recently restored Bulgarian Empire in 1187.
It is subject to extensive research and legitimate interest not only among the Orthodox and Catholic church communities and prominent science and culture figures, but it attracts many pilgrims and ordinary tourists.