Yajnavalkya of Mithila was a legendary sage of Vedic India, credited with the authorship of the Shatapatha Brahmana (including the Brihadaranyaka Upanishad), besides the Yoga Yajnavalkya and the Yajnavalkya Smṛti. He is also a major figure in the Upanishads.
Background
According to tradition, Yajnavalkya was the son of Devarata and was the pupil of sage Vaisampayana . Yajnavalkya was one of the greatest sages ever known. His precepts as contained in the Upanishads (the Brhadaranyaka Upanishad) stand foremost as the crest-jewel of the highest teachings on knowledge of Brahman. Most of the Hindu Laws today are based on the Yajnavalkya Smriti.
Career
As per the demands of his Guru, Yajnavalkya vomited all the knowledge that he acquired from his teacher in form of digested food. Other disciples of Vaisampayana took the form of partridge birds and consumed the digested knowledge (a metaphor for knowledge in its simplified form without the complexities of the whole but the simplicity of parts) because it was knowledge and they were very eager to receive the same.It is believed that Yājñavalkya underwent this process at midday and became ignorant. Consequently , descendents of Yajnavalkya are not considered brahmins at mid-day.