Sofia (sô′ fḗ-yȧ), the capital of Bulgaria since 1878, stands in a valley of the Balkans. It has been improved since 1891, the old Turkish city with its tumbledown houses and crooked streets being replaced by new French houses, wide boulevards, fine public buildings and electric lights. Railroads connect it with Vienna, Constantinople and Belgrade. It is the seat of the National University, which supports three faculties of 49 professors and lecturers and has about 800 students. The city also has a free library. Its trade is mainly in corn, hides and wheat. Its hot mineral springs have been celebrated for centuries. Sofia was known as Serdica by the Romans, and was the seat of a famous council in 343. It belonged to the Bulgarians from the 9th century until 1382, when it was captured by the Turks. In 1878 it was occupied by Russia. Population 102,769.