Windsor Castle has been raided by two masked men, whilst Prince William, Kate Middleton, and their children slept in the estate's Adelaide Cottage.

The offenders entered a farm building and and “made off with a black Izuzu pickup and a red quad bike,” Thames Valley Police told NBC News in a statement Monday.

Prince William and Princess Kate's home was just minutes from the scene of a burglary in which two vehicles were taken.

Police are investigating the incident on the Windsor Castle estate, which is where the Prince and Princess of Wales and their children reside in Adelaide Cottage

Masked thieves reportedly broke into the grounds Windsor Castle while Prince William, Princess Kate and their children were believed to be sleeping at home in their nearby Adelaide Cottage.

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Two men reportedly climbed a six foot fence during the night to steal farm vehicles. The crooks are said to have then driven off in a pick-up truck and on a quad bike that had been stored in a barn.