Evidence has been found that may date salt production in the area back to prehistoric times and the settlement grew up primarily because of its salt deposits. A salt house in Northwich was mentioned in the Domesday Book and by the seventeenth century there were over 200 such 'wyches' in the town producing salt. The manor of Northwich was owned by the Earls of Chester until 1237 and thereafter it became a royal manor. Northwich was granted to the Stanley family in 1484 and in the English Civil War the town was a Parliamentarian stronghold which was garrisoned by Sir William Brereton.
The Smith-Barrys of Marbury Hall were responsible for the discovery of rock salt in the 1670s and this led to the establishment of a number of mines in the area. The industry boosted the town's influence but the lack of good transport links hindered progress. In 1721 an Act of Parliament was passed to make the River Weaver navigable from Winsford to Frodsham Bridge. The building of the Trent and Mersey Canal also increased transport between the Cheshire salt mines and the Potteries. However, a 50ft difference in height prohibited the transfer of cargo between the two waterways. The solution to the problem was the Anderton Boat Lift, built in 1875, which transfered boats hydraulically between the canal and river. The town also gained its rail link in 1863 as part of the Cheshire Midland Railway.
Subsidence became a serious problem for the town from the 1870s as brine pumping was used to extract salt from flooded mines. This led to the dramatic collapse of buildings, canals and roads and the Brine Subsidence Compensation Act was introduced in 1891 to provide compensation for the effects of subsidence. In addition, new buildings reverted to light timber framing which could be jacked up if the ground gave way and, in the worst cases, they could be moved to new locations.
The Brunner Mond chemical company was established in Winnington in 1874 and began to manufacture soda ash using the Solvay ammonia-soda process. Salt was a key raw material for this product and the proximity to the Mid Cheshire saltfields was a major factor in the choice of location for the chemical industry. The waste products from this process were transported to nearby land, where it formed derelict limebeds. Marbury Country Park was the first one of these areas to be regenerated in 1975 and has become a recreational area, followed by a further 323 hectares of public land.
A major programme was launched in 2004 to stabilise the abandoned salt mines beneath Northwich. This work was completed in 1987 and the new 'Vision for Northwich' will involve a range of renovations for the town's buildings. Apart from the chemical industry, the town's major employers currently include Morrisons, Orange and Frank Roberts & Sons bakery. The population of Northwich in 2001 was 19,259 (having risen from 1,338 in 1801).