The event on the Mongolian steppe is scheduled to begin on August 7.

Competitors must complete the race within 10 days, changing their native horses at specially set-up stations at intervals of no more than 40km.

Its promoters say the derby celebrates the horseback messenger system used by the warrior Genghis Khan.

The derby is organised by a British company, The Adventurists, in collaboration with the Mongolia-based Tengri Group.

The race, billed as an event of rider endurance, involves about 1000 horses.

Each station, known as an urtuu, will consist of a small collection of gers - canvas and felt tents - and the horses will be stationed at each point ready for the following leg.

Each urtuu will be hosted by a Mongolian nomadic herding family and manned by a locally trained veterinarian.

The organisers say they have worked with some of Mongolia's top horse breeders and a network of Horse Racing Associations to gather horses for the race.

All will be vet-checked before participation and assessed following competition.