With her husband Prince Philip recovering from a bladder infection, the Queen called on Prince William and Kate Middleton to accompany her on the latest leg of her diamond jubilee tour.
The royal trio headed to the Vernon Park in Nottingham to kick off their two-day tour of the East Midlands and Hertfordshire.
The monarch is expected to visit Nottingham, Burghley, Corby, Stevenage and Hatfield.
Dressed in a turquoise double-breasted coat and matching hat, the Queen greeted thousands of well-wishers lining the route.
While William looked sharp in a navy blue suit, thrifty Kate had recycled a powder blue tweed coat dress that she wore just two months ago.
The Queen unveiled a plaque to honour a Fields in Trust project, which preserves parks as recreational spaces.
Fresh from the the diamond jubilee celebration weekend, the Duke of Cambridge paid tribute to his grandmother.
As patron of the Queen Elizabeth Fields Challenge, a project supported by the Foundation of Prince William and Prince Harry, William gave a speech thanking the Queen for her dedication to her country during her 60 years on the throne.
He said: "The occasion presents the perfect opportunity for me, through my patronage of the Queen Elizabeth II Fields, to pay tribute to the Queen on her diamond jubilee.
"On behalf of Fields in Trust, thank you so much Your Majesty and the Duke of Edinburgh for everything you have done throughout your reign to protect these vital outdoor places for the nation."
IBTimes UK recaps the best moments from the Queen's day in Nottingham...