The county was represented by two Knights of the Shire until 1832, when the number of members was increased to three by the Great Reform Act.
When the parliamentary constituencies were next redistributed under the Representation of the People Act 1918, Cambridgeshire was re-constituted as a single-member Parliamentary County, largely formed from combining the Chesterton Division (excluding areas that were now part of the expanded Municipal Borough of Cambridge) and the Newmarket Division (excluding the city of Ely which was included in the Parliamentary County of Isle of Ely).
The administrative counties of Cambridgeshire and Isle of Ely had been recombined in 1965 and Cambridgeshire was further expanded in 1974 to include Huntingdon and Peterborough under the Local Government Act 1972.
(Although Cambridgeshire contained the borough of Cambridge, which elected two MPs in its own right, this was not excluded from the county constituency, and owning property within the borough could confer a vote at the county election.
In the elections of 1830 and 1831, about an eighth of the votes cast for the county came from within Cambridge itself.