The historic county of Berkshire, in the 21st century region of South East England, was represented in Parliament from the 13th century. This article provides a list of constituencies constituting the Parliamentary representation from Berkshire. In 1889 Berkshire became an administrative county. In 1974 a new shire county of Berkshire lost the Abingdon area to Oxfordshire, while the Slough district was transferred from Buckinghamshire. In 1997 the ceremonial county of Berkshire was divided between several unitary authorities.