The Queen has called for more understanding between generations in her Christmas message.
The Queen attended church at Sandringham
The monarch, who turned 80 this year, said the elderly need to be shown respect and young people need to be "nurtured and guided".
Her message - broadcast at 1500 GMT on radio, TV and online - said that young and old of all faiths have much to offer each other.
Earlier, the Queen attended a service with other royals at Sandringham.
But Prince Harry will not be with his family in Norfolk because he is on duty with the Blues and Royal regiment, and will spend the day in barracks.
The Queen said in her message: "The wisdom and experience of the great religions point to the need to nurture and guide the young, and to encourage respect for the elderly."
The message was recorded at Southwark Cathedral and, for the first time, has been made available as a podcast.
BBC royal correspondent Nicholas Witchell said the aim of the Christmas message was to be as up-to-date, modern and accessible as possible.
The Queen said: "It is very easy to concentrate on the differences between the religious faiths and to forget what they have in common - people of different faiths are bound together by the need to help the younger generation to become considerate and active citizens."
At the Sandringham service, she was joined by the Duke of Edinburgh, Prince Charles and the Duchess of Cornwall, and 24-year-old Prince William.
Zara Phillips joined the other royals
Other regulars at the annual event include Zara Phillips, Peter Phillips, Princess Beatrice, Princess Eugenie, the Princess Royal and the Duke of York.
But royal aides say Prince William's girlfriend Kate Middleton is not joining the family for the Christmas Day celebration.
The Duchess of Cornwall is to spend the rest of the day with her family - daughter Laura Lopes and son Tom Parker-Bowles - as she did last year.
Crowds of well-wishers gathered outside St Mary Magdalene's Church to offer flowers and Christmas tidings to the royals.
Most of the royal party walked to church from nearby Sandringham House.
There was extra security in place at the church on Sunday as the Queen attended a Christmas Eve service.
The royals have a well-trodden Christmas routine which starts with the opening of their presents on Christmas Eve.
After a black-tie dinner in the evening, the corgis are led out and the ladies adjourn, leaving Prince Philip to serve port or brandy to the men.
On Christmas morning, the Royal Family awake to stockings filled with small gifts and fruit at the foot of their beds.
After church, Christmas lunch featuring a giant turkey reared at Sandringham is served with all the trimmings.
The 26 December is an outdoor affair when Prince Philip organises a shoot.