As part of the London Government Act 1963, the borough was established as the London Borough of Barking in 1965. The constituent part of the borough was almost all of Barking and most of Dagenham. In the early days of amalgamation, Barking and Dagenham had approximately 180,000 residents, with Dagenham's northern tip being incorporated into Redbridge, while Barking was incorporated into Newham.
In 1980, Barking and Dagenham became the new name for the borough. In 1994, part of the Becontree estate in Redbridge was transferred to Barking and Dagenham. Mayesbrook Park in that Borough was once part of Jenkins Manor, the seat of the Fanshawe family.
A collection of historic records for Barking and Dagenham Borough and predecessors, Barking and Dagenham Borough, is housed in the Valence House Museum of the Barking and Dagenham Archive Service.
Located on the east of London, the borough is bordered by the River Rom. The west is bordered by the River Roding, while the south is bordered by the London Borough of Newham. The River Thames forms the borough's boundary with the London Borough of Bexley and the Royal Borough of Greenwich to the south. Towards the north, the borough extends from Havering to Redbridge, encircling Chadwell Heath in a thin protrusion. As part of the Metropolitan Green Belt, 530 hectares are located within the borough.
Within the borough, there are three main districts: Barking, Becontree, and Dagenham. It borders five boroughs: Newham, Redbridge, Havering, as well as Greenwich and Bexley.
The London County Council built most of the housing in the borough between 1921 and 1939, mostly escaping slum conditions in London's East End. The Ford Motor Company plant at Dagenham and other new motor and chemical industries during this period led to a significant settlement in the area. Employment has shifted to service sector jobs since the decline of these industries in the 1980s.
In the vicinity of the A13 road, there is a large development of logistics and warehouses. It contains much of the London Riverside area of the Thames Gateway zone and is the site of substantial house building and other developments, including Beam Park. It has been estimated that Barking's principal district will be redeveloped for £500 million.
During the 2011 census, 49.5% of residents identified themselves as white British. As a result of immigration, Barking and Dagenham's white British population has decreased 30.6% between 2001 and 2011, the second largest decrease in the country behind neighbouring Newham. There is a 205% increase in residents who are not British.
The largest decrease of White British occurred in the Longbridge ward (79.8% in 2001 to 35% in 2011), and the Abbey ward, which contains the main Barking area (46.2% to 15.8%). Eastbrook ward had the smallest decrease. Minority groups overwhelmingly consisted of African and Asians.
There were 69,700 households in Barking and Dagenham in 2011, an increase of 3.6% from 2001. The 65+ population has decreased by almost 20% between 2001 and 2011. Among all local authorities in England and Wales, the borough had 21.4% of its population is school-aged (5-19). During the period 2001-2011, the pre-school population in the borough rose by 49.1%, the largest increase in London.