Abingdon was administratively in Berkshire from the creation of the county in the 10th century to 1972. It was once the county town and the most important settlement in the county.
The UK government still recognises the historical counties as existing, as of 2013. Abingdon is traditionally in Berkshire and administratively/ceremonially in Oxfordshire, although soon it will no longer be administratively in Oxfordshire if the new local government plans go ahead and create 'Ridgeway Council', which will merge West Berkshire, South Oxfordshire and the Vale of the White Horse.
The UK government still recognises the historical counties as existing, as of 2013. Abingdon is traditionally in Berkshire and administratively/ceremonially in Oxfordshire, although soon it will no longer be administratively in Oxfordshire if the new local government plans go ahead and create 'Ridgeway Council', which will merge West Berkshire, South Oxfordshire and the Vale of the White Horse.