From monkeying about (Mountain Gorilla, 8pn BBC2) to horsing around; the Doc Martin star follows humans' relationship with horses through the ages, exploring the animal's role in warfare, ceremony, farming, transport, sport and leisure. It's Sunday night, what else do you expect? Today, the horse is still so much a part of our world, in so many ways. On this journey, Martin unravels the true story of how man and horse first got together, what the horse has done for us through the ages, and what the horse still means to us today. Martin begins on his farm in Dorset, where he introduces his equine family, before travelling to Dubai for the grand opening of the Meydan Racecourse and to hear from jockey Frankie Dettori and trainer Luca Cumani. He also visits Mongolia and the South of France, and meets horse whisperer Monty Roberts.