Ilford was historically known as Great Ilford to differentiate it from nearby Little Ilford, in the London Borough of Newham. It is bounded in the west by the North Circular Road and the River Roding and is contiguous with Barking to the south, Gants Hill to the north and Seven Kings to the east.
Ilford was a village and later ward in the ancient Barking parish, in the Becontree hundred of Essex. Ilford formed a civil parish from 1888, with a local board created in 1890, and it became an urban district of Essex from 1894. The council offices were at first in rooms above a shop in Cranbrook Road and, from 1898, council meetings were held in a hired schoolroom in Ilford Hall, High Road, but in 1901 a large town hall, also in the High Road, was completed at a cost of about £30,000. This was designed by B. Woollard in an ornate Renaissance style; it was enlarged in 1927 and 1933. Successive acts provided the council with increased powers and they used these to embark on an expansion of public services, providing sewerage, public baths, an isolation hospital, a fire station, an electricity and tramway undertaking, and several public parks – including Valentine's Park, opened as Central Park in 1898. In 1904, the council also took over the responsibilities of the school board.
In 1926, Ilford was incorporated as the Municipal Borough of Ilford. In the succeeding years, Ilford Corporation made several failed attempts to gain county borough status, which would have given independence from Essex County Council. In 1965 the municipal borough was abolished and its former area was transferred to Greater London to form part of the London Borough of Redbridge.
Redevelopment has destroyed much of the evidence for early Ilford, but the oldest evidence for human occupation is the 1st and 2nd century BC Iron Age earthwork known as Uphall Camp. This was situated between the Roding and Ilford Lane and is recorded in 18th century plans. Roman finds have also been made in the vicinity. A nearby mound called Lavender Mount existed into the 1960s, when it was removed during building work at Howards chemical works. Excavation has shown that the latter may have been a 16th century 'beacon-mound'.
Ilford straddled the important road from London to Colchester, again likely to be of Roman origin, and also (in historic times) was the main crossing point of the marshes, providing the only land access from London to Barking and Tilbury. Barking was the site of Barking Abbey, an important Christian centre from 666AD, and a major fishing port from the Middle Ages. Tilbury achieved importance in the Tudor era as a fort, and later as a port. The Middlesex and Essex Turnpike Trust controlled and maintained this road from 1721. The River Roding was also made navigable for barges as far as Ilford Bridge from 1737.
In 1801 the population of Ilford was 1,724 and by 1841 it had grown to 3,742. In 1839, a railway station was opened on the Great Eastern Main Line and the following year, Ilford was included in the Metropolitan Police District. It had a population of 41,244 in 1901 and occupied an area of . 2,500 houses of the vast Becontree Estate, built by the London County Council from 1921, were within the boundaries of Ilford; the addition caused a rise in population of 11,600 by 1926. The Central Line service of the London Underground began in 1947 and the population peaked in 1951 at 184,706. In 1961 the population was 178,024.
Ilford has a large population of Hindus, Muslims and Sikhs numbering some 30,000. The South Asian community in Ilford speak a variety of languages, including Gujarati, Hindi, Punjabi and Urdu.
Ilford was largely rural until its expansion in the 19th century. This expansion brought about brickworks, cement works and coal yards to service the new buildings, largely centred on the River Roding. These businesses gave way to new industries, such as paper making (commemorated in Mill Lane) and services such as steam laundries and collar making to provide for the new commuting class created by the railway.
During World War II, the factory was heavily damaged by bombing and the company carried out much of its manufacture, with 2000 workers servicing a production line, located in the underground railway tunnel between Wanstead and Gants Hill.
In 1955, the company employed 15,000 workers, in sites throughout Ilford and neighbouring areas, with an extensive research department. Plessey were partners in the development of the Atlas Computer in 1962, and later applied this expertise in developing the System X for the Post Office. The company merged with GEC in 1988, and was acquired by Siemens in 1989, but the site was closed nine years later when the company was reorganised, as part of Marconi plc.