Śaṅkarācārya—an incarnation of Lord Śiva who appeared in South India at the end of the 7th century A.D. to re-establish the authority of the Vedic scriptures. He was a philosopher and lived about three hundred years before Rāmānuja. He did this at a time when India was under the sway of Buddhism, whose tenets deny the authority of the Vedas. He took sannyāsa at a very tender age and wrote commentaries establishing an impersonal philosophy similar to Buddhism, substituting Brahman (Spirit) for the void. He traveled all over India defeating the great scholars of the day and converting them to his doctrine of Māyāvāda, the advaita (non-dualism) interpretation of the Upaniṣads and Vedānta. He left the world at the age of 33; The incarnation of Śiva who appeared about 1400 years ago in South India to propagate Advaita Vedānta. He taught that Brahman is impersonal, there is no individuality apart from Brahman (all souls are really one soul), the cosmic manifestation does not emanate from Brahman, and the cosmic manifestation is without reality, like a hallucination. Though his philosophy is a distortion of the Vedic teachings, his mission was very important. He turned the Indian people away from Buddhism, back to the Vedas. See Advaita, Brahmajyoti, Brahman, Buddhism, Four Vaiṣṇava Sampradāyas and Siddhāntas, Māyāvāda philosophy, Six systems, Vedānta.