What could you give Britain's longest reigning monarch for her birthday?
A day off to "lie about," according to the Queen's grandson Prince Harry.
Speaking to guests at London's Guildhall during a reception to mark her 90th, the young royal touched on his idea of the perfect present for the monarch.
"He said the best birthday present would be to have a day off, so she could lie about and do nothing," Grenada High Commissioner Karl Hood revealed.
Acting High Commissioner for Dominica, Janet Charles, added that while Harry said that he thought the Queen should be putting her feet up, she had wanted to attend the thanksgiving ceremony at St Paul's Cathedral for the public.
She added: "He's such a charming person. I asked him if I could have a photograph with him he said he couldn't as he had to obey the rules. "But he said 'I'm sure we'll meet again'."
Earlier the Queen and Prince Philip, who is 95 today, joined members of the royal family and leading figures from the worlds of politics and religion at a service honouring the milestone.