The concept of the game and its variants date back from the 6th century BC to the 1st century AD. The sport originated from equestrian games played by nomadic Iranian peoples . Polo was at first a training game for cavalry units, usually the Persian king’s guard or other elite troops. A notable example is Saladin, who was known for being a skilled polo player which contributed to his cavalry training. It is now popular around the world, with well over 100 member countries in the Federation of International Polo. It is played professionally in 16 countries. It was an Olympic sport from 1900 to 1936.