The modest town of Belper, Derbyshire was soon to become prosperous by the investment and ingenuity of the Georgian entrepreneur, Jedediah Strutt, and his family who continually developed Cotton Spinning Mills along the banks of the River Derwent. Both the town, and the earlier North Mill, are today dominated by the much later Edwardian East Mill. This is situated on the eastern edge of the original site, and was built by the English Sewing Company in 1912.

Believed to have been completed in 1784, Belper North Mill was the second mill building to have been constructed by Jedediah Strutt on the site, the first being completed a few years earlier. Further expansion of the site continued when the West Mill was developed between 1793-96. At an impressive 201 feet (61m) in length, and powered by two waterwheels, the West Mill also required the creation of the impressive 'horseshoe' weir - a well known feature of the River Derwent today.

The original North Mill continued to operate until the turn of the century, when it was completely destroyed by fire in 1803. The following year the North Mill was rebuilt by Jedediah's son, William, on the foundations of the previous mill, and was technically very advanced for the time.

Having seen the previous building consumed by fire, which was a constant threat from highly flammable cotton dust, William set about designing a building that was essentially fireproof. He replaced previously wooden structures with iron, so developing an 'iron framed' mill. The 'new' North Mill effectively became the forerunner to the modern skyscraper, which is such a familiar site in our present day cities.

To reduce the fire risk, the wooden floors were replaced by cast iron beams, beneath which bricks arches were constructed, each with a nine foot span. The floor itself was initially laid with rubble to level them, on top of which a working surface of bricks was laid. The whole building was shaped like a 'T' the main building being 15 bays wide, and each of the two wings comprising 6 bays. The North Mill also boasted a warm air central heating system, a school room in the attic, and a goods lift between floors.

Strutt's North Mill was powered by a single breast-shot waterwheel designed by Thomas Hewes. The waterwheel was of the suspension type, with power transmitted from its edge by a 'spur' wheel. This, in turn, drove a vertical shaft and, by means of further gearing, drove horizontal shafts running the full length of each floor.

In conclusion, William Strutt's North Mill has been described as the most beautiful and technologically advanced building of its time. Today it plays a central role as part of the Derwent Valley Mills World Heritage Site.