Roskilde is the main city in Roskilde Municipality. With a population of 50,046, the city is a business and educational centre for the region and the 10th largest city in Denmark. Roskilde is governed by the administrative council of Roskilde Municipality. Roskilde has a long history, dating from the pre-Christian Viking Age. Its UNESCO-listed Gothic cathedral, now housing 39 tombs of the Danish monarchs, was completed in 1275, becoming a focus of religious influence until the Reformation. With the development of the rail network in the 19th century, Roskilde became an important hub for traffic with Copenhagen, and by the end of the century, there were tobacco factories, iron foundries and machine shops. Among the largest private sector employers today are the IT firm BEC and GPI, specializing in plastics.