We do not have Adi Shankaracharya's exact biography, as there are various contradictory versions of biographies written by scholars several years after his life time. However, here is a version, which is widely accepted today.
Shankara was born as the only son of Sivaguru and Aryamba in a poor Brahmin family in Kaladi Village in Ernakulam district of Kerala. The most accepted dates about his life time are from 788 to 820 CE. He mastered all Vedas, Upanishads and other scriptures at the very early years of his childhood. When he was eight, with the permission of his mother, he renounced the world to become a Sannyasin.
Shankara was initiated as Sannyasin by Swami Govindapada Acharya, who was a disciple of Mahaguru Gaudapada. As instructed by his master, Shankara went to Kashi (Varanasi) and wrote commentaries on Brahma Sutras, Upanishads and Bhagavad Gita; an extraordinary achievement at the age of sixteen! Then he started the most important mission of his life – Digvijaya, the intellectual journey to conquer the world.
Shankara sitting at the bank of a river with devotees (painting retrieved from web)
Adi Shankaracharya travelled across different parts of India to propagate the philosophy of Advaita Vedanta through debates and discourses. He met philosophers and scholars of different schools of philosophy, debated with them and defeated all of them with the power of his amazing intelligence and spiritual wisdom.
His debate with Mandana Misra, the Chief Scholar in the court of Mahishmathi (the present Maheswar city in Madhya Pradesh), was remarkable. The heated debate lasted for seventeen days and finally Shankara appeared to be winning. Seeing her husband lose, Ubhaya Bharati, the wife of Mandana Misra, who served as the umpire of the debate, challenged Shankara. She asked him questions on Kamashastra, a scripture on sexual and erotic desire. Bharati knew that Shankara had become a monk as a boy, so she thought that he couldn't be knowledgeable on the topic. Yet Shankara did not retreat, but requested a few days’ time for research. With a yoga technique called ‘para-kaya-pravesha’ he entered the body of a recently departed king and from the two wives of the king he learned everything about sex and love within a few weeks. In some versions of the story, Shankara forgot his original task, while he is in the king's body. But one of his disciples finds him and recites some mantras as a reminder. So, within the agreed time he returned to the debate, answered all questions of Bharati, and won the debate. Mandana and Bharati Misra were so impressed that they became Shankara's disciples.
Shankara is often - like Ramana Maharshi- criticised for discarding the world as illusory and unimportant. Ramana explained in a dialogue with a devotee that this is a common misunderstanding:
Question: Is Bhagavan’s teaching the same as Shankara’s?
Ramana (talking about himself as Bhagavan): Bhagavan’s teaching is an expression of his own experience and realization. Others find that it tallies with Sri Shankara’s.
Q: When the Upanishads say that all is Brahman, how can we agree with Shankara that this world is illusory?
R: Shankara also said that this world is Brahman or the Self. What he objected to is one’s imagining that the Self is limited by the names and forms that constitute the world. He only said that the world has no reality apart from Brahman. Brahman or the Self is like a cinema screen and the world like the pictures on it. You can see the picture only so long as there is a screen. But when the observer himself becomes the screen only the Self remains. Shankara has been criticized for his philosophy of Maya (illusion) without understanding his meaning. He made three statements: that Brahman is real, that the universe is unreal, and that Brahman is the Universe. He did not stop with the second. The third statement explains the first two; it signifies that when the Universe is perceived apart from Brahman, that perception is false and illusory. What it amounts to is that phenomena are real when experienced as the Self and illusory when seen apart from the Self. The Self alone exists and is real. The world, the individual and God are, like the illusory appearance of silver in the mother-of-pearl, imaginary creations in the Self. They appear and disappear simultaneously. Actually, the Self alone is the world, the ‘I’ and God. All that exists is only a manifestation of the Supreme.
Q: What is reality?
B.: Reality must always be real. It has no names or forms but is what underlies them. It underlies all limitations, being itself limitless. It is not bound in any way. It underlies unrealities, being itself Real. It is that which is. It is as it is. It transcends speech and is beyond description such as being or non-being.