The county is one of the oldest in England, being reliably dated back to the setting of the traditional county borders by King Alfred the Great of Wessex. Following the reorganisation of local government in 1974, Abingdon (its traditional county town) and the Vale of the White Horse were transferred to Oxfordshire, Slough was added from Buckinghamshire, and Reading became the county town. On April 1, 1998 the county council was abolished and the districts became unitary authorities.
The county takes its name from a large forest of birch trees that was called Bearroc (Celtic for 'hilly') and was originally a transaction of land to King Cenwalh of Wessex. At this time, it only consisted of the northerly and westerly parts of the current county.
