One of the six darshanas of Hindu or Vedic schools and, alongside the Bhagavad Gita and Hatha Yoga Pradipika, are a milestone in the history of Yoga. The Yoga Sūtras of Patañjali are 196 Indian sūtras (aphorisms). The Yoga Sutras were compiled around 400 CE by Patañjali, taking materials about yoga from older traditions. Together with his commentary they form the Pātañjalayogaśāstra.
The Yoga Sutras of Patanjali was the most translated ancient Indian text in the medieval era, having been translated into about forty Indian languages and two non-Indian languages: Old Javanese and Arabic. The text fell into obscurity for nearly 700 years from the 12th to 19th century, and made a comeback in late 19th century due to the efforts of Swami Vivekananda. It gained prominence again as a comeback classic in the 20th century.
In the 20th century the corporate Yoga subculture elevated the Yoga Sutras to a status it never knew previously. Before the 20th century, history indicates the Indian yoga scene was dominated by the Bhagavad Gita, Yoga Vasistha, texts attributed to Yajnavalkya and Hiranyagarbha, as well literature on Hatha Yoga, Tantric Yoga and Pashupata Yoga rather than the Yoga Sutras of Patanjali.
Scholars consider Patanjali's Yogasutra formulations as one of the foundations of classical yoga philosophy.
Example via www.ramdass.org: “Yoga Sutras of Patanjali” translated by Swami Satchidananda