The Prince of Wales and his sons arrived back in Britain yesterday as the Royal Family gathered to mourn the Queen Mother.

Charles, William and Harry cut short their skiing holiday to fly home from Klosters, in the Swiss Alps.

The Queen took the rare step of waiving royal protocol to allow the heir to the throne and his eldest son to share the same plane.

The princes joined other members of the family at evensong at Royal Chapel of All Saints, in the grounds of Windsor Castle, in the evening before returning to their Highgrove home in Gloucestershire.

The three princes arrived at Windsor after flying to RAF Northolt on the BAe146 royal jet from Zurich, after a two-hour car journey from Klosters.

As they set off from the Walserhof Hotel yesterday morning, a grim-faced Charles, in a dark suit and black tie, gave a brief wave to staff gathered outside.

His sons, also in dark suits, sat behind him in the back of the blue Audi. They were understood to be particularly upset at seeing their father so devastated by the loss of his grandmother, to whom he was devoted.

In the past few months, as her health declined, he was making increasingly frequent trips across the courtyard from his St James's Palace apartment to her Clarence House home to see her.

Her trusted aide and friend, Billy Tallon, would be at the door to let him in. The Prince last saw his grandmother when he dropped in to see her at Windsor last Thursday, on his way to Switzerland.

In Klosters, he and the teenage princes had two full days of skiing before they heard the news.

They were informed on Saturday at the end of a day on the slopes, in which they raced each other and joked around with friends.

The Prince of Wales had just returned to the Walserhof Hotel when he was telephoned by the Queen at about 3.30pm UK time, 15 minutes after her 101-year-old mother passed away in her sleep.

Charles then broke the news to his sons in his hotel room when they returned from the Parsenn slopes, just above Klosters, about half an hour later.

The boys spent the evening comforting their father.

The family ate a light evening snack, and the Prince was said to have eventually managed a restful night.

Yesterday evening, about 16 senior Royals solemnly filed into a small Windsor chapel where earlier the Queen Mother's coffin had been placed on simple oak trestles.

The Queen had requested a short service in her mother's memory after the coffin had been taken to the chapel from nearby Royal Lodge.

First to arrive was the Duke of York, driving a black Jaguar with a male companion, followed five minutes later by a convoy of six cars.

In the first car, driven by the Duke of Edinburgh, was the Queen by his side, dressed in black with a simple diamond brooch. Behind her was Sophie, Countess of Wessex, and next to her the Earl.

They were followed by a dark Vauxhall Omega, driven by the Prince of Wales, Prince William seated next to him and in the back seat his younger brother Prince Harry.

Next came the Princess Royal, accompanied by children Zara Phillips and Peter, a Range Rover driven by Viscount Linley and Lady Sarah Chatto and two cars believed to be carrying security officers, bringing up the rear.

Also among the mourners were: Princess Margaret's daughter, the recently bereaved Lady Sarah Chatto with her husband Daniel.