Shankaracharya was an influential Indian philosopher and theologian who lived in the early 8th century CE. He is best known for consolidating the doctrine of Advaita Vedanta, which emphasizes the non-dual nature of reality, asserting that the individual soul (Atman) and the ultimate reality (Brahman) are one and the same. His teachings aimed to reconcile the differences between various schools of thought in Hinduism. He traveled extensively across India, establishing four major monasteries, known as mathas, in different regions to promote his philosophy. Shankaracharya wrote numerous texts, including commentaries on the Upanishads, Bhagavad Gita, and Brahma Sutras, which continue to influence spiritual thought and practice in Hinduism today.