Derby is a city and unitary authority area in the East Midlands region of England. It lies upon the banks of the River Derwent and is located in the south of the ceremonial county of Derbyshire, of which it was traditionally the county town. In the 2011 census, the city had a population of 248,700.As home to Lombe's Mill, the first factory in the world, Derby is considered a birthplace of the Industrial Revolution. With the arrival of the railways in the 19th century, and due to its strategic central location, the city grew to become a foremost centre of the British rail industry.Today, Derby is an internationally renowned centre for advanced transport manufacturing, home to the world’s second largest aero-engine manufacturer, Rolls-Royce, and Derby Litchurch Lane Works—the UK's only remaining train manufacturer. The Toyota Manufacturing UK's automobile headquarters is found just South of the city at Burnaston.HistoryOriginsThe Roman camp of 'Derventio' was probably at Little Chester/Chester Green; The site of the old Roman fort is at Chester Green. Later the town was one of the 'Five Boroughs' (fortified towns) of the Danelaw.