Surrey is one of the historic counties of England, located south of the River Thames, in south east England. The constituency comprised the whole county. (Although Surrey contained eight towns which were boroughs for at least part of the time the county was a constituency - Bletchingley, Farnham, Gatton, Guildford, Haslemere, Kingston upon Thames, Reigate and Southwark - each of which elected two MPs in their own right, these were not excluded from the county constituency, and owning property within the boroughs could confer a vote at the county election.)
The county franchise, from 1430, was held by the owners of freehold land valued at 40 shillings or more. Each voter had as many votes as there were seats to be filled. Votes had to be cast by a spoken declaration, in public, at the hustings, which took place in the county town of Guildford. The expense and difficulty of voting at only one location in the county, together with the lack of a secret ballot contributed to the corruption and intimidation of voters, which was widespread in the unreformed British political system.
The expense, to candidates, of contested elections encouraged the leading families of the county to agree on the candidates to be returned unopposed whenever possible. Contested county elections were therefore unusual.
Where there was only one candidate of a party in successive elections, for the same number of seats, change is calculated on the party vote. Where there was more than one candidate, in one or both successive elections for the same number of seats, then change is calculated on the individual percentage vote.