At the time of the Norman occupation, Belper was part of the land centred on Duffield held by the family of Henry de Ferrers.

The Domesday Survey records a manor of "Bradley" which is thought to have been somewhere in the vicinity of the Coppice. At that time it was probably within the Forest of East Derbyshire which covered the whole of the county east of the Derwent. It was possibly appropriated by William de Ferrers, 4th Earl of Derby at some time after it was disafforested in 1225 and became part of Duffield Frith.

The town's name is often said to be a corruption of the name Beaurepaire 
(beautiful retreat), the name given to a hunting lodge, the first record being a charter of 1231. This would have been the property of Edmund Crouchback, 1st Earl of Lancaster who died in 1296, the record of his estate mentioning "a capital mansion".

There may have been Roman settlements in and around the river. Later, the Domesday Book 
speaks of a hamlet known as Bradley or Bradelei having "8.5 Households, 32 villagers, 8 smallholders, 10 slaves, 1 priest." The name is now reflected in the store De Bradelei Mills in Chapel Street.

From the 11th century the Ferrers family controlled the area from a massive Norman castle at Duffield and in the 13th century a Manor House and Chapel were built. By the 14th century there is a deer park within Duffield Frith with a hunting lodge and chapel.

The coal deposits of Derbyshire are frequently associated with ironstone and its availability together with charcoal and coal meant that Belper became a centre for nailmaking, from as early as the twelfth century.

In 1314-15 the Duchy of Lancaster recorded two forges producing iron bars for chapel windows, nails and spikes. Horseshoes and nails were supplied to huntsmen visiting the Royal Forest.

By the end of the eighteenth century there were around 500 nailer's workshops in the town. Nailmaking continued during the Industrial Revolution, but was eventually superceded by the cotton mills.

At the beginning of the industrial revolution Belper's population was only around 500. A hundred years later in 1830 this figure had risen to around 8,000. The reason was the availability of work in the mills and good workers' housing.

The construction of Jedediah Strutt's mills brought many workers to Belper. By 1792 Belper had five mills and new rows of cottages to house the workers. The Strutt family also provided a chapel and schooling for their employees and child workers.

Belper was one of the first 'mill towns', as a progression of events in Derby and nearby Cromford. The industrialist Jedediah Strutt was initially a partner of Richard Arkwright and built a water-powered cotton mill at Cromford, followed by his own at Belper. In 1784 he built the North Mill, and across the road joined by a gangway, the West Mill.

In 1803 the North Mill was burnt down to be replaced by an innovative new structure designed to be fireproof. Other extensions followed, culminating in the East Mill in 1913, a present day Belper landmark. To this day the mill derives power from the river, using turbine-driven electrical generators.

The Strutt family were great benefactors of the town for some 150 years, providing for their workers employment, housing, education and even food from its model farms.

Much of the mill site was cleared in the 1960's. All that nowadays remains of Strutt's Mills is the large East Mill and the smaller North Mill, preserved as part of the Derwent Valley Mills heritage sites.
The weir at Belper used to power four mill complexes. Even now it provides all the electricity for the North and East Mills.

Below the mill complex, the River Derwent is spanned by a fine stone bridge of 1795, replacing the old one washed away in a flood. The beautiful River Gardens offered boating on the river and brass band music at the bandstand.

In 1820 Belper was the first place in the UK to get gas lighting, at a works erected by the Strutts at Milford. Demand was such that in 1850, the Belper Gas and Coke Company was formed, with a works in Goods Road. The railway was built by George Stevenson in 1838 and was thought to be a marvel of engineering.

John Ward and George Brettle established a hoisery business which once employed hundreds of people. The George Brettle Warehouse, built in classical style in 1834, still survives in Chapel Street.