Ashoka spread Buddhism all over India and Ceylon by

Ashoka became a upasaka of Buddha. He established an intimate relation with the Buddhist Sangha and is said to have become a monk. He undertook Dharma yatra instructing Dharma to the people. He took up pilgrimages to the birth place of the Sakyamuni. To spread the message of Dharma to the vast extent of his empire. He appointed officers in charge of religious propagation. They were called Dharma Mahamatras, to spread his ideas of Dharma and spread Buddhism all over India and Ceylon.