The Queen will see a garden created in memory of her late sister Princess Margaret for the first time during her visit to Oxford tomorrow.

Her Majesty will spend the morning at the Rothermere American Institute in South Parks Road, where she will officially open the memorial.

The new garden is the creation of hotel and clothes designer Anouska Hempel, who first gained fame as an actress in the 1960s and 1970s.

The Queen - who celebrated her 80th birthday a fortnight ago - will meet Ms Hempel and trustees of the Institute before unveiling a stone.

Dr Paul Giles, director of the institute, said: "The wonderfully designed garden will provide both a social and a tranquil contemplative space, as well as being a fitting memorial to Princess Margaret."

As part of her visit, The Queen will also take a tour of Oxford University Press' Oxford Dictionary of National Biography in St Giles.

Robert Faber, director of the Oxford Dictionary of National Biography (DNB) project, said: "The Oxford DNB is a national resource. It's a great honour for us."

At mid-morning the Queen will officially open the Oxford Castle development and walk around the site, which includes a hotel, apartments, restaurants and heritage centre.

County council leader Keith Mitchell said: "The visit by Her Majesty places the royal seal of approval on our fantastic project."

The Queen will also unveil a plaque. At midday, the tour will end with lunch at Christ Church.

* Get your free Union Jack flag with every Oxford Mail bought from from John Irvin's stand in St Ebbe's, Oxford, today from 11am to 4pm. See tomorrow's Mail for full details of the royal itinerary.