A renowned horse whisperer who enjoyed a decades-long friendship with the late Queen Elizabeth II and once moved the Queen Mother to "tears" has passed away at age 91, his daughter revealed. © Getty Images Monty Roberts has died aged 91"For more than eight decades, he dedicated his life to changing the way people understand and work with horses. His friendship with the late Queen© Getty Images The horse trainer had a close friendship with the late QueenThe horse trainer was invited to give a demonstration at Windsor Castle in 1989 by the Queen Mother. After connecting with the royal family, Monty struck up a decades-long friendship with the late Queen Elizabeth, bonding over their shared love of animals. © Getty Monty Roberts was in attendance at the Queen's state funeralHe admitted: "It was to say goodbye.