1885–1918 • The Borough of Hertford; • The Sessional Divisions of Bishop's Stortford and Cheshunt; • Parts of the Sessional Divisions of Hertford and Ware; and • In the Sessional Division of Aldbury, the parishes of Great Hadham and Little Hadham.
1918–1950 • The Borough of Hertford; • The Urban Districts of Bishop's Stortford, Cheshunt, Hoddesdon, Sawbridgeworth, and Ware; • The Rural Districts of Hadham and Ware; and • The Rural District of Hertford parishes of Bayford, Bengeo Rural, Bengeo Urban, Bramfield, Brickendon Liberty, Brickendon Rural, Hertingfordbury, Little Amwell, Little Berkhamsted, St Andrew Rural, St John Rural, Stapleford, and Tewin.
Minor changes to boundaries. 1950–1955 • The Borough of Hertford; • The Urban Districts of Bishop's Stortford, Cheshunt, Hoddesdon, Sawbridgeworth, and Ware; • The Rural District of Ware; • The Rural District of Braughing parishes of Albury, Braughing, Brent Pelham, Furneux Pelham, High Wych, Little Hadham, Much Hadham, Stocking Pelham, and Thorley; and • The Rural District of Hertford parishes of Bayford, Bengeo Rural, Bengeo Urban, Bramfield, Brickendon Liberty, Brickendon Rural, Hertingfordbury, Little Amwell, Little Berkhamsted, St Andrew Rural, St John Rural, Stapleford, and Tewin.
Nominal changes only to reflect restructuring of rural districts. 1955–1974 • The Borough of Hertford; • The Urban District of Welwyn Garden City; and • The Rural Districts of Hatfield, Hertford, and Welwyn.
Significant changes with only the Municipal Borough and the part of the Rural District of Hertford retained. The remainder of the constituency formed the basis of the new County Constituency of East Hertfordshire. The Urban District of Welwyn Garden City and the Rural District of Welwyn were transferred from St Albans; the Rural District of Hatfield from Barnet; and the remainder of the Rural District of Hertford from Hitchin. The constituency was abolished in the redistribution taking effect for the
February 1974 general election. The Municipal Borough and Rural District of Hertford were included in the new constituency of
Hertford and Stevenage, with remaining areas forming the new constituency of
Welwyn and Hatfield. ==Members of Parliament ==