Gauḍapāda

Gauḍapāda is regarded as the founder of systematic Advaita Vedānta. His Māṇḍūkya-kārikā (also Gauḍapāda-kārikā or Āgama-śāstra), a verse commentary on the brief Māṇḍūkya Upaniṣad, is the earliest extant treatise to articulate strict non-dualism — including the controversial doctrine of ajātivāda ('non-origination,' the view that nothing is ever truly produced), which shows engagement with, and possible influence from, Mahāyāna Buddhist thought. Tradition makes him the teacher of Govinda Bhagavatpāda, who in turn taught Śaṅkara, placing him roughly a century or two before Śaṅkara. His exact dates are unsettled (estimates range across the 6th–8th centuries), and his biography is almost entirely a blank.