It's a long, long trail - 75 miles to be ridden in two days. The course is over the wildest part of Exmoor and presents the ultimate test for both horse and rider.

Each May competitors come from all over Britain, but this film follows just three of them - two from Somerset and one from Gloucestershire.

It is also the story of Smokey, Witham Golden Colonel (better known as Opal) and a horse called Herbie.