Updated 7:39 AM ET, Mon February 27, 2012
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Riders set off in the early morning to embark on a grueling 120-kilometer endurance marathon through the deserts of the United Arab Emirates. Alysen Miller/CNN
A convoy of land cruisers follow the horses, issuing instructions to their riders during each of the lap of the 30 km course. Alysen Miller/CNN
After each lap, the horses are subjected to medical checks. This is to ensure they are physically capable of surviving another lap. Alysen Miller/CNN
Not all of the 50 horses who begin the race make it to the end, with less than a quarter of the field finishing this event. Alysen Miller/CNN
The Arabian horse is said to be a gift to mankind from Allah. Today's racing thoroughbreds can trace their DNA to three stallions imported to Britain in the 18th century. Alysen Miller/CNN