Buckingham Castle was situated in the town of Buckingham

Buckingham

Buckingham is a town situated in north Buckinghamshire, England, close to the borders of Northamptonshire and Oxfordshire. The town has a population of 11,572 ,...

, the former county town of Buckinghamshire

Buckinghamshire

Buckinghamshire is a ceremonial and non-metropolitan home county in South East England. The county town is Aylesbury, the largest town in the ceremonial county is Milton Keynes and largest town in the non-metropolitan county is High Wycombe....

, on the north side of the River Ouse

River Great Ouse

The Great Ouse is a river in the east of England. At long, it is the fourth-longest river in the United Kingdom. The river has been important for navigation, and for draining the low-lying region through which it flows. Its course has been modified several times, with the first recorded being in...

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The castle was first mentioned in documentary sources in 1154-64 and was possibly demolished 1208-1215. It was possibly held by the Giffard family. It was levelled in 1777 for the churchyard which now occupies the site.