With the gradual spread of Buddhism to distant lands, India got in touch with the foreign lands. For example, Afghanistan became an important centre of Buddhism. This spread of Buddhism cannot be attributed to one person or authority rather it was the collective efforts of the missionaries, pilgrims and travellers who were patronised by the ruler.
The most important work was done by the missionaries sent by Ashoka to central Asia in order to spread the teachings of Buddha. Even, Kanishka, a Kushana ruler, sent missionaries to spread the idea that Buddha was a god on earth and his idols were made to worship across the world. Pilgrims and travellers travelled through the Silk Route to spread the Buddhist ideologies. For example, a Buddhist monk Kumarajiva went to China and stayed there for several years to spread Buddhism.