South Yorkshire, in the north of England, is home to 1.34 million people (nearly 9% of England's population), covering an area of approximately 696 square miles (1,800 km2). This makes it the third most populous county in England after Greater London and West Midlands, and the second most densely populated county behind Greater London. The area consists of five metropolitan boroughs: Barnsley, Doncaster, Rotherham, Sheffield and Wakefield. It was formally created in 1974 under the Local Government Reorganisation Act of 1972 by merging several smaller administrative counties together.