Sandipani (Sandeepani) was Krishna's guru (teacher) during his education at Ujjain. According to tradition, Krishna and Balarama studied under Sandipani, and as guru dakshshina (teacher's fee), Krishna retrieved his guru's lost son from the demon Panchajana who lived in a conch shell. Vyasa was the author of the Mahabharata (and Krishna's grand-uncle), Parashurama was a warrior-sage who taught Bhishma and Karna, and Vasudeva was Krishna's father.