In India, haṭha yoga is associated in popular tradition with the Yogis of the Natha Sampradaya through its traditional founder Matsyendranath. Almost all hathayogic texts belong to the Nath siddhas, and the important ones are credited to Matsyendranath’s disciple, Gorakhnath or Gorakshanath. Matsyendranath, also known as Minanath or Minapa in Tibet, is celebrated as a saint in both Hindu and Buddhist tantric and haṭha yoga schools. However, James Mallinson associates haṭha yoga with the Dashanami Sampradaya and the mystical figure of Dattatreya. According to the Dattatreya Yoga Śastra, there are two forms of haṭha yoga: one practiced by Yajñavalkya consisting of the eight limbs of ashtanga yoga and another practiced by Kapila consisting of eight mudras.
Currently, the oldest dated text to describe haṭha yoga, the 11th-century CE Amṛtasiddhi, comes from a tantric Buddhist milieu. The oldest texts to use the terminology of hatha are also Vajrayana Buddhist. Later haṭha yoga texts adopt the practices of haṭha yoga mudras into a Saiva system, melding it with Layayoga methods which focus on the raising of kuṇḍalinī through energy channels and chakras.
In the 20th century, a development of haṭha yoga, focusing particularly on asanas (the physical postures), became popular throughout the world as a form of physical exercise. This modern form of yoga is now widely known simply as “yoga”.
Hatha yoga is a branch of yoga. It shares numerous ideas and doctrines with other forms of yoga, such as the more ancient system taught by Patanjali. The differences are in the addition of some aspects, and different emphasis on other aspects. For example, pranayama is crucial in all yogas, but it is the mainstay of Hatha yoga. Mudras and certain kundalini-related ideas are included in Hatha yoga, but not mentioned in the Yoga Sutras of Patanjali. Patanjali yoga considers asanas important but dwells less on various asanas than the Hatha yoga texts. In contrast, the Hatha yoga texts consider meditation as important but dwell less on meditation methodology than Patanjali yoga.
The Hatha yoga texts acknowledge and refer to Patanjali yoga, attesting to the latter’s antiquity. However, this acknowledgment is essentially only in passing, as they offer no serious commentary or exposition of Patanjali’s system. This suggests that Hatha yoga developed as a branch of the more ancient yoga. According to P.V. Kane, Patanjali yoga concentrates more on the yoga of the mind, while Hatha yoga focuses on body and health. Some Hindu texts do not recognize this distinction. For example, the Yogatattva Upanishad teaches a system that includes all aspects of the Yogasutras of Patanjali, and all additional elements of Hatha yoga practice.