Sheffield is a city and metropolitan borough in South Yorkshire, England. The name derives from the River Sheaf which runs through the city. It is a historic part of Yorkshire, although some southern suburbs have been annexed from Derbyshire.
The city is in the eastern foothills of the Pennines, and the valleys of the River Don and its four tributaries, the Loxley, the Porter Brook, the Rivelin and the Sheaf. Sixty-one per cent of Sheffield's entire area is green space, and a third of the city lies within the Peak District national park. There are more than 250 parks, woodlands and gardens in the city, which is estimated to contain around 4.5 million trees.
Sheffield played a crucial role in the Industrial Revolution, with many significant inventions and technologies having developed in the city. In the 19th century, the city saw a huge expansion of its traditional cutlery trade, when stainless steel and crucible steel were developed locally, fuelling an almost tenfold increase in the population. Sheffield received its municipal charter in 1843, becoming the City of Sheffield in 1893.