1885–1918 • The Sessional Divisions of Dengie, Orsett, and Rochford; and • The civil parishes of Rainham and Wennington.
Formed primarily from the abolished South Division of Essex, together with the southern part of the abolished East Division (Dengie peninsular). See below for areas covered. 1918–1945 • The Urban Districts of Grays Thurrock, Shoeburyness, and Tilbury; • The Rural Districts of Orsett and Rochford; and • Part of the Rural District of Billericay.
Gained southernmost parts of Chelmsford Division of Essex, including Billericay. The area between River Crouch and River Blackwater (Dengie peninsular), including Burnham-on-Crouch, was transferred to Maldon and the westernmost area, including Rainham, to Romford. Parts comprising Southend-on-Sea County Borough created as a separate Parliamentary Borough. 1945–1950 • The Urban Districts of Benfleet, Billericay, Canvey Island, and Rayleigh; • The Rural District of Rochford; and • Part of the County Borough of Southend-on-Sea. This was implemented by the Redistribution of Seats Order 1945 under which South East Essex was divided into two constituencies. As a consequence, the
Urban District of Thurrock (created largely from amalgamating the Urban Districts of Grays Thurrock and Tilbury and the Rural District of Orsett) was formed as the new
Thurrock Division of Essex. Other marginal changes resulting from changes to local authority boundaries.'' Following the
First Periodic Review of Westminster constituencies the seat was abolished. The bulk of the Division, comprising the Urban Districts of
Benfleet,
Billericay,
Canvey Island and
Rayleigh, formed the new County Constituency of
Billericay. The
Rural District of Rochford, and the parts of the County Borough of Southend-on-Sea (
Shoeburyness), included in the new constituency of
Southend East.
1955–1974 • The Urban Districts of Benfleet, Canvey Island, and Rayleigh; and • The Rural District of Rochford.
Re-established as a County Constituency. Benfleet, Canvey Island and Rayleigh were transferred back from Billericay, and Rochford from Southend East. 1974–1983 • The Urban Districts of Benfleet, Canvey Island, and Rayleigh.
The Rural District of Rochford was now transferred to Maldon. On abolition for the second time, Benfleet and Canvey Island (which now comprised the
District of Castle Point) formed the new constituency of
Castle Point. Rayleigh had been incorporated into the
District of Rochford and was included in the new constituency of
Rochford.
Areas covered ==Members of Parliament==