Although the exact origins of the game are unknown, it most likely began as a simple game played by Iranian equestrian nomads in Central Asia, with the current form originating in Iran (Persia) and spreading east and west. In time polo became a Persian national sport played extensively by the nobility. Women played as well as men. During the period of the Parthian Empire (247 BC to 224 AD), the sport had great patronage under the kings and noblemen. According to the "Oxford Dictionary of Late Antiquity", polo (known as "čowgān" in Middle Persian, i.e. chovgan), was a Persian ball game and an important pastime in the court of the Sasanian Empire (224–651). It was also part of royal education for the Sasanian ruling class. Emperor Shapur II learnt to play polo when he was seven years old in 316 AD. Known as "chowgan", it is still played in the region today.