Although the Kushan Empire fell after only a few centuries to the White Huns, the Buddhist Tradition remained strong throughout the area, attracting monks and pilgrims of all sorts to be a part of the reputation it had managed to build up over the years.
This was a time where Buddhism had spread very strongly throughout India and parts of Asia and had become a very popular tradition in these parts. However, itwas only just really beginning to make a true mark on the Middle Eastern and central Asian states by the 1st century, and the Valley of Bamiyan helped to Bring Buddhism even farther west. The art styles and philosophical teachings appealed to many people, especially along the Silk Road route where beliefs and ideals could be spread fairly easily. It was repeatedly mentioned in Chinese texts and thus became a major centre, well known among the Silk Road travellers. Because of this, many people had easy access to information and teachings, thus the spread quickened and its influence is very visible among the great Silk Road sites that still stand today.
The Bamiyan valley has cliffs that stretch 15,000 feet tall and runs for some 30 miles eastwards. It was a major thoroughfare, fairly safe and easy to traverse, and so many travelled through it yearly. It was a connecting point between Kabul and Turkestan, and thus was only natural for it to be a popular route. Over the years, it is likely that Buddhist Monks settled in to stay in this lush valley, where perhaps they could spread their teachings and live in a pleasant environment. The statues of Bamiyan that made the place so well known and were documented in nearly every script of travellers that passed through were built sometime in the fourth century, by the White Huns. They were invaders to the Valley, but made Bamiyan into the premiere Buddhist pilgrimage site of the world for many centuries thanks to these statues. It was what officially marked the valley as an independent Buddhist State, and people all around were awed by their size and majesty. But while Buddhism was moving westwards, Islam was beginning to move in an easterly direction. The Buddhist age lasted another 400 years, until the year 900 when Islam began to arrive in full and settle in for good. The kingdoms of Bamiyan, now fully Islam, flourished for a few hundred years until the Mongols invaded and Genghis Khan sent in his most beloved grandson to command the army. The grandson was killed however, and Genghis himself vowed to come down hard on them, with no mercy. And that was exactly what he did. In 1222, the Mongol army stormed Bamiyan, the citadels and the villages and anything that breathed in the valley was mercilessly slaughtered. This was a devastating blow, of course, as now the Mongols, otherwise known as the Hazara’s, occupied the area, thus distancing the valley from the rest of Afghanistan and discouraging travellers from passing through anymore. Perhaps one of the main distancing factors would have to be the fact that the Hazara’s do not and will not practice Islam, thus not really having much respect from the rest of Islamic Afghanistan. And so, the once glorious valley lost its reputation and perhaps, was forgotten by many over the years.