) is a city and unitary authority area in the ceremonial county of Derbyshire, England.It lies on the banks of the River Derwent in the south of Derbyshire, of which it was traditionally the county town.
Derby and Derbyshire were among the centres of Britain's Industrial Revolution.
In 1717, Derby was the site of the first water powered silk mill in Britain, built by John Lombe and George Sorocold, after Lombe had reputedly stolen the secrets of silk-throwing from Piedmont in Italy (he is alleged to have been poisoned by the Piedmontese as revenge in 1722).
A hundred years later, Bonnie Prince Charlie set up camp at Derby on 4 December 1745, whilst on his way south to seize the British crown.
The prince called at The George Inn on Irongate, where the Duke of Devonshire had set up his headquarters, and demanded billets for his 9,000 troops.
The first mill opened in Nottingham in 1770 and was driven by horses.
In 1771 Richard Arkwright, Samuel Need and Jedediah Strutt built the world's first commercially successful water-powered cotton spinning mill at Cromford, Derbyshire, developing a form of power that was to be a catalyst for the Industrial Revolution.
He abandoned his invasion at Swarkestone Bridge on the River Trent just a few miles south of Derby.
As a testament to his belief in his cause, the prince – who on the march from Scotland had walked at the front of the column – made the return journey on horseback at the rear of the bedraggled and tired army.
In the 2011 census, the population of the city was 248,700, with 1,543,000 in the wider metro area.
Having earlier been a county borough between 18, Derby gained city status in 1977.
Toyota Manufacturing UK's automobile headquarters is south west of the city at Burnaston. Later the town was one of the 'Five Boroughs' (fortified towns) of the Danelaw, until it was captured by Lady Aethelflaed of Mercia in July 917, subsequent to which the town was annexed into the Kingdom of Mercia.