Sheffield is a city in South Yorkshire, England, whose name derives from the River Sheaf which runs through it. The city serves as the administrative centre of the City of Sheffield. It is historically part of the West Riding of Yorkshire and some of its southern suburbs were transferred from Derbyshire to the city council. It is the largest settlement in South Yorkshire.
The city is in the eastern foothills of the Pennines and the valleys of the River Don with 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 and is the fifth largest city in England. There are more than 250 parks, woodlands and gardens in the city, which is estimated to contain around 4.5 million trees. The city is south of Leeds and east of Manchester.
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. International competition in iron and steel caused a decline in these industries in the 1970s and 1980s, coinciding with the collapse of coal mining in the area. The Yorkshire ridings became counties in their own right in 1889, the West Riding of Yorkshire county was disbanded in 1974. The city then became part of the county of South Yorkshire; this has been made up of separately-governed unitary authorities since 1986. The 21st century has seen extensive redevelopment in Sheffield, consistent with other British cities. Sheffield's gross value added (GVA) has increased by 60% since 1997, standing at £11.3 billion in 2015. The economy has experienced steady growth, averaging around 5% annually, which is greater than that of the broader region of Yorkshire and the Humber.