The marathon is meant to commemorate Pheidippides, a Greek soldier, who ran from Marathon to Athens when the Persians had been defeated at Marathon. It is said that after running the distance and announcing the victory, he collapsed and died. Today the marathon is 26.2 miles. However, the actual distance from Marathon to Athens is only 21.4 miles. The first modern Olympic marathon was 24.9 miles. During the London games of 1908, the original course was set from Windsor Castle to the Olympic Stadium... but the distance was increased to 26.2 miles so it could end at the royal viewing stand for Edward VII. This is now considered to be the official distance to this day. Damn British.