Oxfordshire is a southern midland county of England, bounded on the north by Warwickshire and Northamptonshire, on the east by Buckinghamshire, on the south by Berkshire and the Thames, and on the west by Gloucestershire. Its area is 768 square miles.
The county is drained by the Thames with its tributaries the Windrush, Evenlod, and Cherwell. The Oxford and Birmingham Canal affords access to the midland coal fields.
The region was part of the kingdom of Mercia. There are remains of a few old castles, Saxon and Norman, and vestiges of early monastic establishments. Oxfordshire was the scene of important events during the reign of King John and during the Civil Wars, when Oxford, the capital, was the capital of the Royalists.