If Prince Philip can't come to us on Christmas Day ...

The Royal Family interrupted their traditional Christmas Day schedule yesterday to visit the Duke of Edinburgh in hospital as he recovered from emergency heart surgery.

Six of Prince Philip's grandchildren, including Princes William and Harry, went to see him at Papworth Hospital in Cambridgeshire, where he was taken on Friday after suffering chest pains, and had a coronary stent fitted. Princesses Beatrice and Eugenie, and Peter and Zara Phillips also visited.

Last night, a spokesman for Buckingham Palace said the Duke was "getting much better" but would remain under observation. Earlier, the royals celebrated Christmas at Sandringham, the Queen's private residence in Norfolk. Prayers were said for the Duke during the traditional Christmas Day church service at St Mary Magdalene Church on the estate. Afterwards, the family – including, for the first time, the Duchess of Cambridge – greeted some of the thousands of well-wishers waiting outside.

The Queen attended the service, along with the Prince of Wales and Duchess of Cornwall, Prince Harry and the Queen's grand-daughter, Zara Phillips, with her husband Mike Tindall, the England rugby player.

The famously irascible Prince Philip, 90, was said to be eager to be discharged from Papworth. He has always prided himself on keeping active and appears to have little patience with illness.

Eight years ago, when the Palace denied reports that he had prostate cancer, the Duke gave short shrift to anyone who suggested he was unwell, shouting at one Sandringham estate worker: "Do I look bloody ill?"

Nevertheless, on Friday night there were fears that he was on the verge of a heart attack. Tests confirmed the Duke had a blocked coronary artery and needed a stent fitted – a process in which a tiny balloon is pushed into the artery and inflated to clear an obstruction. A mesh sleeve remains fixed in place when the balloon is removed.

His illness added poignancy to the Queen's annual Christmas message, recorded a fortnight earlier, in which she spoke of how, in times of hardship, people "often find a source of courage rising up from within" and in a crisis communities "break down barriers and bind together to help one another".