The pentathlon (as opposed to the modern pentathlon) was an athletics event in the Olympic Games and other Panhellenic Games of Ancient Greece.
The name derives from Greek words for "five competitions." The five events were stadion (a short foot race), wrestling, which were also separate events, and the long jump, javelin throw and discus throw, which were not separate events. Pentathletes were considered to be among the most skilled athletes, and their training was often part of military service - each of the five events was thought to be useful in battle.
The winner of the stadion was considered the champion of the entire Games, and was often the only name remembered in connection with a particular Games. If the same man won the long jump, discus throw, and javelin throw, there was no need hold the stadion and wrestling events, although they would still be held separately. Wrestling was held in a sand pit, at the Olympic Games outside the Temple of Zeus, while the other events were all held in the stadion (or stadium, from which the name of the race was taken). Wrestling and the discus throw were essentially the same as their modern versions, but the others had slight differences. The javelin throw used a leather strap, rather than having the athlete grip the shaft of the javelin itself (this probably made the javelin travel farther than a modern javelin does). The stadion was a sprint of 200 yards (or about 180 meters), longer than the modern 100 meter sprint, but shorter than the other ancient running events.
The long jump is perhaps the most unusual, compared to the modern version. A long jumper used weights called halteres to propel himself farther, and his jump probably consisted of three separate leaps; otherwise, distances of known jumps (which are often as far as 50 feet) would seem to be impossible.
Competitors in the javelin and discus throws were given five throws each, and only their farthest throw would count. It is possible that the long jump was also done five times.
All of these events were performed naked.