Along with a congregation that included pop stars, political leaders and 30 members of the Windsor clan, the Queen attended a national service of thanksgiving to mark the official celebrations for her 80th birthday.
Wearing the radiant smile that has characterised her appearances this year, the much-loved monarch paused outside St Paul's Cathedral to acknowledge the well-wishers gathered there. She was joined by Prince Philip, as well as Prince Charles, with his sons, William and Harry.
Normally known for wearing vivid block colours, the octagenarian - who has been showing a renewed flair for elegance during her milestone festivities - had chosen an outfit with scalloped sleeves in an unusual shade of silver-grey.
Meanwhile the Queen's young female relatives put on a display of finery that has become customary in this special year. Princess Beatrice, who is fast growing into a sophisticated young lady, arrived with her father the Duke of York, wearing a tailored chocolate coat accessorised with a striking headpiece.
A dramatic feathered confection also added a stylish touch to Lady Gabriella Windsor's ice blue suit. Elsewhere Lord Linley's wife Serena was chic in a fitted coat with silver flats, while Lady Rose Windsor's polka-dot dress had a retro-glam feel to it.
Prime Minister Tony Blair, pop veterans Sir Cliff Richard and Dame Shirley Bassey were also among the 2,300 guests at the service. On Saturday - her official birthday - the Queen attends the Trooping the Colour parade. The tradition of two birthdays dates back to the time when royal planners wanted to be assured of good weather for outdoor events.