The Jireček Line is an imaginary line through the ancient Balkans that divided the influences of the Latin (in the north) and Greek(in the south) languages until the 4th century. It goes from near the city of Laçi in modern Albania to Serdica (now Sofia, inBulgaria) and then follows the Balkan Mountains to Odessus (Varna) on the Black Sea. The placing of the line is based on archaeological findings: most of the inscriptions found to the north of it were written in Latin, while most of the inscriptions found to the south were in Greek. This line is important in establishing the area where the Romanian and Aromanian people were formed (see Origin of Romanians), it is considered that a Latin-speaking people may have formed near this area since there are Latin Vlach speakers to the north and south of it. It was originally used by the Czech historian Konstantin Jireček in 1911 in a history of the Slavic people.