Pashtun culture is based on Islam and Pashtunwali, which is an ancient way of life, as well as speaking of the Pashto language and wearing Pashtun dress. The culture of the Pashtun people is highlighted since at least the time of Herodotus (484-425 BC) or Alexander the Great, when he explored the Afghanistan and Pakistan region in 330 BC. The Pashtun culture has little outside influence and, over the ages, has retained a great degree of purity.