He also started on a tour of India to establish his philosophy. Soon he established himself as the authority on Vedanta philosophy. His vast knowledge and deep spiritual insights won him many disciples and debates. He met the leaders of different schools of thought. He went to all the celebrated seats of learning. He challenged the learned men to discussion, argued with them and defeated them. The most famous debate that Shankara won was the one he had with Mandana Misra, who was the chief Pundit of the court of Mahishmati. Mandana Misra was an authority on Karma Kanda (the ritualistic portion of the Vedas). Since Shankara taught Jnana Kanda (the path of knowledge), he agreed to have a debate with Mandana Misra. At first Mandana Mishra was skeptical about having a philosophic debate with a sannyasi. Once the debate started he began loosing on every point of argument that was raised and finally he had to accept defeat.
Then his wife Bharati who was also a great scholar challenged Shankara into a debate. When she wanted to debate on the subject of marital life and obligations, Shankara being a celibate since childhood had no understanding of marital relations, takes a three-month break from the debate to learn about this subject. The legend says that he infused his spirit into the body of a dying king and spent the next three months learning about this subject. After the three months he returns and wins the debate. Mandana and his wife become his disciples.
During this time he received the message of his mother’s illness. After she died he performed her last rites despite opposition from the ritualistic kinsmen who felt that the last rites cannot be performed by a sanyasi. Shortly after this his Guru also passed away. Shankara paid his last respects to Govinda and established a temple in his honour. Shankara then proceeded to Prayaag, where he met Kumararila and Prabhaakara. Kumararila was very much responsible for the decline of Buddhism. When Prabhaakara and his son, Prthiviidhara were defeated in a debate, both of them became Shankara’s disciples. After his mother’s death, Shankara traveled twice throughout India enjoying the patronage and protection of kings and scholars. Even members of the royal families gave up their wealth and position to become his disciple.
Shankara continued to travel around the land refuting all objectionable practices. Shankara founded the dasanami order of sanyasis. It is divided into ten groups namely Aranya, Ashrama, Bharati, Giri, Parvata, Puri, Sarasvati, Sagara, Tirtha and Vana.
He established Maths in four places:
- Vimala Pitha at Puri with which Aranyas and Vanas are associated with the mantra ‘prajnanam brahman‘.
- Kalika Pitha in Dvaraka, associated with Tirthas and Ashramas, with the mantra ‘tat tvam asi.’
- Sarada Pitha in Sringeri, associated with Bharatis, Puris and Sarasvatis with the mantra ‘aham brahmaasmi.’
- Jyoti Math in Badrinath associated with Giri, Parvata and Sagara and the mantra ‘ayam atman brahman.’
He also installed the Sri Chakaras in many temples such as the Kamakshi temple of Kanchi, Nara Narayana temple of Badri and Guhyesvari temple in Nepal. He placed Sri Sureswaracharya at the head of the Math in Sringeri, Sri Padmapada in Dvaaraka, Sri Totaka in Badri and Hastamalaka in Purii.
Shankara finally proceeded to Kedarnath higher up in the Himalayas. He became one with the Linga in his thirty-second year. This happened around 820 A.D.