Vic Clapham

The latest edition of the world's greatest ultra-marathon takes place on Sunday. Catch up on the history - along with some fascinating facts and anecdotes - of a race that's internationally recognised for the body-sapping challenge it poses and the camaraderie it fosters among its thousands of participants.

Some of the world's most extreme races are held in South Africa, where elite athletes – and ordinary people – pit themselves against the unforgiving elements and huge distances. Perhaps the most well-known is the Comrades Marathon, a gruelling 90km run between Durban and Pietermaritzburg.

The 2011 Comrades Marathon, which took place on 29 May, was the most competitive edition yet. For the first time in the history of the race, top Ethiopian runners entered, posing a great threat to defending champions. The race also saw an increase in entrants from the UK, US, Australia and Brazil.
• South Africa's toughest endurance challenges