Similar to much of south-west Essex, the town expanded rapidly in the late 19th century, forming part of the conurbation of London and becoming a suburb. It became part of the Metropolitan Police District in 1839 and has been part of the London postal district since its inception in 1856. The ancient civil parish of Leyton, historically in the Becontree hundred, became an urban district in 1894 and gained municipal borough status in 1926. In 1965, it merged with the neighbouring municipal boroughs of Walthamstow and Chingford to form the London Borough of Waltham Forest local authority area upon the formation of the Greater London administrative area.