Patanjali
Codifier of the Yoga Sutras

Codifying the Yoga Sutra: Patanjali codified, or compiled in a systematic way, the art and science of Yoga in the Yoga Sutras. The Yoga Sutras succinctly outlines the art and science of Yoga for Self-Realization. Nothing new was created with the Yoga Sutras, but rather the ancient practices were summarized in an extremely organized and terse way. While the Yoga Sutra itself is ancient, archaeological evidence and other texts suggest that the methods described in the Yoga Sutras were being practiced as early as 3000 BCE. Oral tradition states that the date may be even earlier.

Dates: Scholars estimate that Patanjali lived some time between 400 BCE and 200 AD, though they are in disagreement about these dates. While the scholars debate the actual dates of Patanjali, oral tradition accounts for the apparent time differences by explaining that the name Patanjali is a surname, and is the name of a lineage and school of teachers, students, and sages, rather than being only one person. However, for convenience sake, Patanjali is spoken of as a single person, who might have been founder of the lineage. Although Patanjali is a surname of the lineage, there have also been several individuals with the name Patanjali, which may or may not have been related with the lineage relating to the Yoga Sutras of Patanjali.

Oral tradition: In addition, the Yoga traditions are historically oral traditions, and some say the Yoga Sutras were not written down for at least a couple hundred years after they were systematized by Patanjali. During that period it was the custom for the entirety of the Yoga Sutras to be memorized as a part of the practice. This type of learning is still done today by a few teachers and students, though many of them now do this as an intellectual study of Sanskrit, rather than as an aid to practice and direct experience.

Unbroken teaching: While the lineage of Patanjali may or may not have continued in unbroken sequence in the visible or recorded traditions in the plains of India, the practices of the Yoga Sutras have continuously been practiced by the sages of the Himalayas.

The longer history: "The tradition of India's philosophical lineages is lost in antiquity. According to one Tantric text (Shri-vidyarnava) there were seventy-one teachers from Kapila, the founder of Sankhya [considered to be the philosophical basis of Yoga], to the greatest proponent of Vedanta, Shankaracharya who taught at the end of the seventh and beginning of the eighth century A.D.; and from Shankara to the present day a lineage of up to seventy-six teachers has been enumerated. If this appears to be a long time, the reader might find interesting the fact that in approximately 1400 B.C. the Brhadaranyaka Upanishad (VI.5.1-4) enumerated sixty-six teachers up to that time. Patanjali in his work on grammar speaks of eighty-four thousand rshis [enlightened sages who teach from their experience]. Within the Indian tradition it is almost impossible to assign a date to the rshis..." (Pandit Usharbudh Arya, Yoga Sutras of Patanjali, Volume 1, 1986)

Vyasa 

The ancient sage Vyasa has written a commentary on the Yoga Sutras, which is widely recognized as the leading expansion on the very brief sutras developed by Patanjali. Vyasa is considered to be an enlightened sage in his own right, with his comments or explanations considered as authentic as those of Patanjali. It is common for Yoga Sutras translations and commentaries by other people to also contain the descriptions by Vyasa.