Sheffield ⁱ/ˈʃɛfiːld/ is a city and metropolitan borough of South Yorkshire, England. Its name derives from the River Sheaf, which runs through the city. Historically a part of the West Riding of Yorkshire, and with some of its southern suburbs annexed from Derbyshire, the city has grown from its largely industrial roots to encompass a wider economic base. The population of the City of Sheffield is 555,500 (2010 est.) and it is one of the eight largest regional English cities that make up the English Core Cities Group.