The monarch – who turns 88 on 21 April – was snapped making the most of the warm spring weather on Wednesday morning by going for a trot with her head groom Terry Pendry in the grounds of Windsor Castle.
She was kitted out for the jaunt in jodhpurs and one of the brightly-coloured silk scarves she favours to cover her head during off duty moments.
For the outing Her Majesty chose her fell pony Carltonlima Emma, who is reportedly one of her favourite mounts.
Horses compete with Corgis as one of the Queen's most enduring passions, and her annual pilgrimage to the Epsom Derby is when the usually calm and collected monarch can be seen in her element, cheering on her horses.
Elizabeth II not only enjoys riding, she possesses a knowledge of equestrian matters that rivals the professionals who manage her 25 or so animals.
And the monarch is a keen breeder, often buying horses from Kentucky to maintain lineage.
Even when on official business, there is always room for her hobby. During her historic trip to Ireland in 2011 – the first by a reigning monarch in 100 years – she took time out to visit a thoroughbred breeding facility.
Although the Derby continues to elude her, she has been victorious in all other flat racing events, collectively known as 'The Classics'.
Trophies for the four iconic British races - the 1,000 and 2,000 guineas, the Oaks and the St Leger - can all be found on her mantelpiece.