Roberts created the Join-Up International organization, which was named after the core concept of his training method. Roberts didn't own the champion German racehorse Lomitas, but he saved the horse's racing career by curing his severe starting-gate phobia, leading the owner to name Roberts the horse's honorary manager. Roberts was born in Salinas, California and was the son of horse trainer Marvin Roberts, who authored his own self-published book, Horse and Horseman Training, in 1957. The first was the 1997 documentary BBC/PBS Monty Roberts: The Real Horse Whisperer. In 2023, a documentary about the relationship formed between Roberts and Queen Elizabeth II was released, called The Cowboy and the Queen.