The centrist hypothesis was popular in the 19th century when it played a positive role in the Slovak national movement. According to this theory, the Slovak language is the remnant of the Proto-Slavic language spoken in the Middle Danube region before the great migration of the Slavs. This hypothesis is based on Nestor's Primary Chronicle and was supported by Matej Bel and several notable members of the movement, like Pavel Jozef Šafárik, Anton Bernolák and Ľudovít Štúr. Most modern scholars oppose the opinion about the Slavic homeland being in the Middle Danube, but the theory was revived in the 20th century by a Russian linguist named Oleg Trubachyov.