The city's name is derived from Ceolmaer's ford[citation needed] which was close to the site of the present High Street stone bridge.

On 7 September 1199, following the commissioning of a bridge over the River Can by Maurice, Bishop of London, King John granted to William of Sainte-Mère-Eglise a royal charter for Chelmsford to hold a market, marking the origin of the modern town.

He was attended by his council, headed by the temporary Chancellor ... the new chief justice ... the royal chancery ... Their formidable task in Chelmsford was to draft, engross, date, seal and despatch by messengers riding to the farthest corners of the realm, the daily batches of commissions, mandates, letters, orders and proclamations issued by the government not only to speed the process of pacification of the kingdom, but to conduct much ordinary day-to-day business of the Crown and Government."

In the 17th century many of the victims of Matthew Hopkins (the self-styled "Witchfinder General") spent their last days imprisoned in Chelmsford, before being tried at the Assizes[8] and hanged for witchcraft.

The GHQ Line part of the British hardened field defences of World War II runs directly through Chelmsford with many pillboxes still in existence to the north and south of the city.

Hylands Park, the site of the former annual V Festival, hosted a prisoner of war camp, and from 1944 until it was disbanded in 1945, was the headquarters of the Special Air Service (SAS).

Some of the factory was converted into luxury apartments and a health club although most of the site was demolished to make way for the Rivermead Campus of the Anglia Ruskin University.

[19][20][21][22] The announcement to make Chelmsford a city had been made on 14 March 2012 by the Lord President of the Privy Council and Deputy Prime Minister, Nick Clegg.

In 1934 the borough was enlarged by gaining 1,659 acres (671 hectares) from Chelmsford Rural District, including parts of the parishes of Broomfield, Springfield, Widford and Writtle.

[29] was abolished on 1 April 1974 and its former area was combined with most of the remainder of the rural district to form the larger Borough of Chelmsford which was granted city status by Royal Charter in 2012.

Following the opening of the Chelmer and Blackwater Navigation in 1797, cheaper transportation and raw materials made milling and malting the main industries until the 1850s, when increasing prosperity created a local market for agricultural machinery.

Foundries and engineering works followed including Fell Christy at his Factory (In later years known as Christy Norris Ltd) on the corner of Kings Road and Broomfield Road opened 1858, closed 1985, Coleman and Moreton, Thomas Clarkson (Steam Omnibus manufacturer and Founder of the Eastern National Bus Company) and Eddington and Stevenson (makers of traction engines).

Chelmsford is a centre for national electricity suppliers operating within the industrial and commercial sectors, with both EnDCo and F&S Energy headquartered within the city.

Its central Essex location and good public transport links make the city ideal for revellers, commuters and tourists to visit from surrounding areas.

In 1922, the world's first regular wireless broadcasts for entertainment began from the Marconi laboratories at Writtle near Chelmsford – Call sign '2MT' in what was little more than a wooden hut.

They vacated the site in April 2008 with the remaining operations moved to nearby Basildon, bringing to an end more than 100 years of the Marconi name in Chelmsford.

[37] The New Street factory was scheduled to be redeveloped starting in 2010,[38] but this fell through when site owners Ashwell Property Group entered administration in December 2009.

Only the Grade II listed water tower, The 1912 front building façade, the New Street cottages, and the power house will remain.

'The Village' housing development now occupies the site with road names such as Rookes Crescent, Evelyn Place, Crompton Street and Parkinson Drive as tributes to the former occupant.

[citation needed] Most of the former Hoffman New Street factory was demolished during the summer of 1990 and the site is now occupied by the sprawling Rivermead Campus of the Anglia Ruskin University.

[52] The company has received 13 Queen's Awards for Technology in its history, most recently in 2006 for low light imaging devices and in 2004 for thyratrons for cancer radiotherapy treatment.

[54] In December 2005 the Company underwent an initial public offering (IPO) allowing its main shareholders (InterContinental Hotels Group, Whitbread, Pernod Ricard) to realise their investments.

Proposals for a bypass of Chelmsford connecting the A12 interchange at Boreham (junction 19) and the A131 were put forward for public consultation by Essex County Council in 2006; the preferred route was announced in March 2007.

It comprises the creation of 7.9 km (4+15⁄16 mi) of two-lane dual carriageway and junctions connecting to the A12 and A131, it will sever 10 footpaths/bridleways and involve almost entirely greenfield construction.

Recently, plans were revealed for Waterside, a large development of shops, bars and restaurants on the banks of the River Chelmer on derelict land near the Essex Records Office, at the end of Wharf Road.

Dating from 1730, the house was much damaged by fire and vandalism by the time of the sale, but has since been completely restored by Chelmsford City Council and is now available for weddings and other private hires including conferences.

A major £5 million extension and redevelopment scheme opened in January 2010 and the museum now includes exhibits and interactive displays focusing on Crompton, Marconi, and Hoffmann, as well as illustrating the development of the town and city from prehistory up to modern times.

Opened in July 1791 and built by local architect and Essex county surveyor John Johnson, it features a Portland stone façade.

Concrete Canvas continued in May 2023, an additional 43 artworks were added to the street art trail including work by local artists and international names such as DFace and Shephard Fairey.

[95] For the local Muslim community, the majority of whom are Bengali and Pakistani, the Main Jamia Masjid mosque is located on Moulsham Street at the junction with Parkway.