PRINCE William stunned staff at a pizza restaurant at the Oxford Castle when he dropped in for a meal with his girlfriend.

The Prince, 24, treated girlfriend Kate Middleton to a pizza and a bottle of Chardonnay at Pizza Express in the £40m Oxford Castle complex, which was officially opened by the Queen at a special ceremony in May.

The Prince is the latest Royal visitor to Oxfordshire this year. Last month, Princess Anne witnessed bun-throwing in Abingdon as she joined Royal Charter celebrations, and Prince Charles visited Oxford to address the annual conference of the Prayer Book Society.

Staff said Prince William arrived unannounced at 8pm on Saturday, and was shown to a table for nine to celebrate a friend's graduation.

Prince William tucked in to a £6.95 Fiorentina pizza and chose the house Chardonnay, costing £11.55, as two bodyguards watched from a nearby table. Girlfriend Kate chose a salad nicoise.

Trainee manager Kirsty Kinnear, who was on duty on the night, said: "Prince William and his girlfriend just turned up with some friends - we had no idea they were coming.

"Staff were very excited but the Prince was very understated, so we just gave him the normal service.

"They sat downstairs very discreetly and we tried to respect their privacy - we didn't take any photos.

"Our waiter Steve Byrne served them and said the Prince was very friendly. He didn't say anything in particular, it was just general chit-chat."