Borujerd is a city and the capital of Borujerd County, Lorestan Province in western Iran. At the 2006 census, its population was 227,547 in 59,388 families. Among the existing modern cities in Iran, Borujerd is one of the oldest reported at least since the 9th century. In Sassanid Empire, Borujerd was a small town and region neighboring Nahavand. Gaining more attention during Great Seljuq Empire in the 9th and 10th centuries, Borujerd stood as an industrial, commercial and strategic city in Zagros Mountains until the 20th century. In its golden ages, Borujerd was selected as the state capital of Lorestan and Khuzestan region during Qajar dynasty in the 18th and 19th centuries.