No single volume has ever examined in depth the history of the Olympic marathon, or why thousands of runners line up across the world to run those 26.2 miles each year. With the Olympic Games returning, for the first time in a century, to their ancient home in Athens, here are the stories behind the ultimate running challenge. Did Pheidippides the Greek ever perform the feat of endurance the famous victory at Marathon is alleged to have inspired? It matters not: Spiridon the Greek most certainly did in 1896, when the modern Olympic Games were born in Athens. Twenty-four men's marathons have come and gone under the five-ringed flag, but no Greek runner has ever won it again. The marathon has become a world event. Touched by politics and its own fair share of controversy, more than anything, the marathon is the measure of athletics heroes. What does it take, apart from dogged determination, to run an Olympic marathon? No athlete now would try what Zatopek did half a century ago. Where the first marathon runner brought news of a victorious army, an army of support staff now stands behind the marathon man or woman, while athletics training has evolved to levels Spiridon would never have dreamt of.