A National Thanksgiving service is being held in London, June 15, to celebrate Britain's Queen Elizabeth II's 80th birthday.

The ceremony is being held at St Paul's Cathedral and is scheduled to start just after 11 a.m.

A host of important guests are gathering to attend the service, including Britain's Prime Minister Tony Blair and Dame Shirley Bassey.

According to the Royal.gov.uk website, the official occasion, the latest eventto mark the monarch's milestone jubilee, is expected to gather over 2,000guests.

One hundred members of the general public have also been invited, following a ballot draw.

The Queen's actual birthday is in April, but official celebrations have continued for the last three months.

The Queen's official birthday is on Saturday, June 17, 2006.

The royal tradition of two birthdays dates back to the time when, ifmonarchs were born in winter, the weather was deemed unsuitable for outdoor events.

The church service will be led by The Dean of St Paul's, Reverend Dr. John Moses, and will also feature a sermon from the Archbishop of Canterbury, Dr Rowan Williams.

After the ceremony the Queen and her husband, the Duke of Edinburgh, Prince Philip, will go for a short walk in the courtyard at St Paul's Church before attending a birthday lunch.

The hearty meal, prepared by Scottish celebrity chef Nick Nairn, willreportedly feature delicacies such as Scottish fish and roe deer.

Chef Nairn is renowned for his culinary excellence and said he was feeling anxious about catering for the monarch.

Nairn was quoted on the BBC website as saying, "The caterers who are doing the actual coal face work have phoned up saying that they've lost 40 portions of venison. But these things do tend to happen in these big events and I'm sure that it will all resolve itself satisfactorily. But at the moment, nerves are beginning to settle in."

In the evening, the royal couple will attend an event in honor of PrincePhilip's 85th birthday.

Prince Philip's actual birthday was on Saturday, June 10, which he celebrated with a private ceremony at the Windsor castle.

Tonight, the Massed Bands of the Royal Marines are set to perform on HorseGuards for the royal couple's entertainment.

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