LONDON (AP) – Surrounded by family, friends and hundred of guests, Queen Elizabeth II attended a service of thanksgiving at Windsor Castle on Sunday at the end of five days of festivities marking her 80th birthday.

The queen, who has reigned for 54 years, attended the service with her 84-year-old husband Prince Philip, their three sons, their daughter and their grandchildren. Also among the 700 guests were former prime ministers Margaret Thatcher and John Major, Prince Charles’ sons, William and Harry, and numerous other royals.

The Dean of Windsor, the Right Rev. David Conner, praised the queen for “calmness, serenity and stillness.”

“Your Majesty, not so much through word as by unselfconscious good example, you encourage us, you give us heart,” he said, telling the queen that she helped Britons “understand that happiness, fulfillment and humanity can be gleaned from self-forgetfulness.”

The queen celebrated on Friday with a walk among well-wishers and dinner with her closest family members at Kew Palace in suburban London.

On Saturday, 80 cars went on display at Buckingham Palace, the queen’s London home. A “Bullnose” Morris Oxford Tourer represented 1926, the year the queen was born, while a Jaguar XK150 was 2006’s vehicle.