Britain’s longest-reigning monarch, Queen Elizabeth the II is celebrating her 96th birthday on Thursday in Sandringham.

To mark her birthday, the Queen was seen in a picture, standing in between two ponies and reflecting her lifelong interest in horses.

The Queen will be joined by family and friends after she travels to her Norfolk estate, by helicopter.

She is expected to stay in a cottage on the estate particularly liked by her late husband, Prince Philip.

Sources say the picture was taken at Windsor Castle, where the Queen now mostly stays, and shows her with two Fell ponies, who will appear in the forthcoming Royal Windsor Horse Show.

Meanwhile, some people have started sending the queen birthday wishes. On twitter, the Duke and Duchess of Cambridge have wished the Queen happy birthday.

They referred to her as an “inspiration to so many across the UK, the Commonwealth and the world.”

This gesture was shared with a photo of the Queen and Prince Philip with seven of their great-grandchildren.