Matsyendranath

Matsyendranath (or Macchindranath), from the 9th-10th century, was one of the eighty-four Mahasiddhas, and is the patron deity of Nepal. He was guru of Gorakshanath, with whom he founded the school of Hatha yoga, one of the branches of Yogic practices. He is revered by both Hindus and Buddhists.

Matsyendranath is considered by many to be the founder of the Nath Sampradaya of sadhus. While the Naths had actually been known much earlier, from the time of Dattatreya, Macchinndranath did initiate a revival by combining the three viewpoints of Siddha, Tantra, and Nath philosophy.

Scholarship has tentatively associated Macchindranath with Luipa who is venerated as a Mahasiddha in the Vajrayana Buddhist tradition.

(source: Wikipedia)

Origins of Tantra

"In the Nath Tradition, legend ascribes the origin of Tantra to Dattatreya, a semi-mythological yogi and the assumed author of the Jivanmukta Gita ("Song of the liberated soul"). Matsyendranath is credited with authorship of the Kaulajnana-nirnaya, a voluminous ninth-century tantra dealing with a host of mystical and magical subjects, and occupies an important position in the Hindu tantric lineage, as well as in Tibetan Vajrayana Buddhism."

(source: Wikipedia)