[1] On 1 April 1974 it was split between the borough of Dartford and the new district of Sevenoaks.
The civil parishes of Ash-cum-Ridley, Eynsford, Eynsford-Crockenhill, Farningham, Fawkham, Hartley, Horton Kirby, Swanley, and West Kingsdown, all of which became part of Sevenoaks District, are sometimes still collectively referred to as the 'Northern Parishes'.
Longfield civil parish originally went to Sevenoaks, but was transferred to Dartford Borough in 1987.
[2] At the time of its dissolution it consisted of the following 15 civil parishes.
Elections for one-third of the seats were held every year.