Ambedkar believed that the Mahar people were an ancient Buddhist community of India who had been forced to live outside villages as outcasts because they refused to renounce their Buddhist practices. He considered this to be why they became untouchables and he wrote a book on this topic, entitled Who were the Shudras?.
Dikshabhumi, a stupa at the site where Ambedkar embraced Buddhism along with many of his followers
Ambedkar studied Buddhism all his life, and around 1950s, Ambedkar turned his attention fully to Buddhism and traveled to Sri Lanka (then Ceylon) to attend a convention of Buddhist scholars and monks.While dedicating a new Buddhist vihara near Pune, Ambedkar announced that he was writing a book on Buddhism, and that as soon as it was finished, he planned to make a formal conversion back to Buddhism.Ambedkar twice visited Burma in 1954; the second time in order to attend the third conference of the World Fellowship of Buddhists in Rangoon. In 1955, he founded the Bharatiya Bauddha Mahasabha, or the Buddhist Society of India. He completed his final work, The Buddha and His Dhamma, in 1956. It was published posthumously.
After meetings with the Sri Lankan Buddhist monk Hammalawa Saddhatissa, Ambedkar organized a formal public ceremony for himself and his supporters in Nagpur on 14 October 1956.
After publishing a series of books and articles arguing that Buddhism was the only way for the Untouchables to gain equality, Ambedkar publicly converted on October 14, 1956, at Deekshabhoomi, Nagpur. He took the three refuges and the Five Precepts from a Buddhist monk, Bhadant U Chandramani, in the traditional manner. Accepting the Three Refuges and Five Precepts from a Buddhist monk in the traditional manner, Ambedkar completed his own conversion, along with his wife Dr. Savita Ambedkar(nee Sharada Kabir). He then proceeded to convert a large number (some 500,000) of his supporters who were gathered around him.He prescribed the 22 Vows for these converts, after the Three Jewels and Five Precepts. The conversion ceremony was attended by Medharthi, his main disciple Bhoj Dev Mudit, and Mahastvir Bodhanands Sri Lankan successor, Bhante Pragyanand. He then traveled to Kathmandu in Nepal to attend the Fourth World Buddhist Conference. Ambedkar would die less than two months later, just after finishing his definitive work on Buddhism. His work on The Buddha or Karl Marx and “Revolution and counter-revolution in ancient India” remained incomplete.
Many Dalits employ the term “Ambedkar(ite) Buddhism” to designate the Buddhist movement, which started with Ambedkars conversion. Many converted people called themselves as “Nava-Bauddha” i.e. New Buddhists.
After receiving ordination, Ambedkar gave dhamma diksha to his followers. The ceremony included 22 vows given to all new converts after Three Jewels and Five Precepts. On 16 October 1956, Ambedkar performed another mass religious conversion ceremony at Chanda. He prescribed 22 vows to his followers: