Here in Britain, London is limbering up for its big marathon race on April 25. As the tens of thousands of runners go through their final training stages (in 2009 more than 24,000 finished the race), we are reminded that the Marathon run dates back to the ancient Greeks, to the battle of Marathon in 490 BC.

Even more importantly, we are reminded that this year, 2010, is the 2500th anniversary of that battle and the first ever ‘Marathon’. Or is it?

To be sure, the battle of Marathon, the battle in which a small Athenian force, without Spartan help, managed to rout the massive invading armies of Persia, happened in 490 BC (on either August 12 or September depending on how you interpret the ancient calendars).

To be sure, it was an Athenian victory that was celebrated time and time again in ancient Greece and became part of Athens’ civic identity. But what about the Marathon run itself?

The story goes that a single soldier Pheidippides ran back from the battlefield at Marathon to Athens (a distance of about 42 km – the current marathon distance) to announce the Athenian victory before dropping dead.

When the first modern Olympics was held in Athens in 1896, it was suggested to the President of the games, Pierre de Coubertin, that the ‘Marathon’ would make a good Olympic event. The first winner was a Greek, Spyros Louis, and since then, marathons have taken place all over the world, although the exact distance of 42.195km wasn’t fixed until 1908 when the Olympics came to London.

The problem is that it’s very hard to find any trace of the Pheidippides story in the contemporary ancient sources. Herodotus, who wrote his history of the Persian wars just 70 years after the battle, has Pheidippides running from Marathon to Sparta and back (a much longer distance of 150 miles each way) to ask for Spartan help before the battle started.

But he then says that, after the battle, all the Athenian troops marched quickly back to Athens to defend the city in case the Persians tried to land again and attack from the south. We have to wait until the First Century BC before we hear about the journey from Marathon to Athens being made by a single runner and until 180 AD, in the writings of Lucian, for it to be crystallized into the story we know today.

So marathon runners everywhere – just be thankful the modern Marathon doesn’t cover the distance Pheidippides may originally have run and good luck!

Michael C Scott is the author of ‘From Democrats to Kings – The Brutal Dawn of a New World from the Downfall of Athens to the Rise of Alexander the Great’ www.michaelcscott.com