1 The history and Evolution of Yoga can conveniently be divided into the following four broad categories:

2 VEDIC  PERIOD Period from approximately 5000 B.C.E years until the second century C.E.  (4500-2500 B.C.E) The actual word "yoga" surfaced around 1500 B.C.E
2.1 Aryan barbarians brought with them Brahmanism, a complex religious tradition based on sacrifice and ritual that formed the basis of modern-day Hinduism, and introduced the concept of yoga.
2.1.1 It revolved around the idea of sacrifice as a means of joining the material world with the invisible world of the spirit.
2.1.2 External rituals - doing things out in the world
2.2 The sacred scriptures of Brahmanism, known as the Vedas, contain a mixture of incantations and instructions in both poetry and prose.
2.2.1 Three books used by priestly class of Brahmins introduced.
2.2.1.1 Rig Veda.
2.2.1.1.1 Collection of hymns
2.2.1.1.2 Composed by seers (rishi)
2.2.1.1.3 Date back
2.2.1.2 Sama Veda
2.2.1.3 Yajur Veda
2.2.2 A fourth book called Atharva Veda introduced for all which included spells and incantations for everyday living

3 PRECLASSICAL PERIOD Period of approximately 2,000 years (4500-2500 B.C.E) until the second century C.E.
3.1 Upanishads (the conclusion of the revealed literature),  composed around 1800 B.C.E +
3.1.1 The Upanishads give an accurate knowledge of Ultimate Reality.
3.1.1.1 Collection over 200 scriptures describing the inner vision of reality resulting from devotion to Brahman
3.1.1.2 Subject matter comprise
3.1.1.2.1 Brahman
3.1.1.2.2 Atman
3.1.1.2.3 the Individual Self
3.1.2 Method and approach - Jnana (knowledge or contemplation)
3.1.2.1 Upanishads bring a conclusion and describe the goal of the Veda
3.1.2.2 The point of starting is the hearing  (Word of mouth) of Vedanta texts from a profound and sympathetic teacher.
3.1.2.2.1 They are part of the Shruti (heard/revealed/revelation) literature
3.1.2.3 The conviction of the absolute nature of Self brought about by hearing  and ratiocination if verified by experience based upon deep meditation of Self
3.2 Bhagavad-Gîtâ ( Gîtâ for short) composed around 500-550 B.C. E.  The Bhagavad-Gita (Lord's Song), is a small part of the Mahabharata, and the oldest Yoga Scripture of which we have knowledge
3.2.1 central point: To be alive means to be active and, if we want to avoid difficulties for ourselves and others, our actions must be benign and also go beyond the grip of the ego
3.2.1.1 The Bhagavad Gita builds on and incorporates doctrines found in the Upanisads
3.2.2 Method and approach Three facets must be brought together and integrated into a total life-style
3.2.2.1 Bhakti (loving devotion)
3.2.2.2 Jnana (knowledge or contemplation)
3.2.2.3 Karma (selfless-action)
3.2.2.4 Results in
3.2.2.4.1 yoga is skill in action (2:50)
3.2.2.4.2 evenness of mind (2:48)
3.2.2.4.3 'he who loves Me with faith is the highest Yogin' (6:47)
3.2.3 The Gita is presented as a dialogue on the actual battle-field between the ’incarnate God‘, Krishna and Prince Arjuna

4 CLASSICAL PERIOD Râja-Yoga Period of approximately (100-200 C.E)  The Yoga-Sutra is equated with Raja-Yoga (the 'royal' yoga
4.1 Yoga-Sûtra . This Sanskrit text is composed of just under 200 aphoristic statements
4.1.1 Composed around second century C.E 4.1.2 Central believe: Each individual is a composite of matter ( prakriti ) and spirit ( purusha ).
4.1.3 There are 196 aphorisms (Sutras) and 4 Chapters (Pada)
4.1.4 The Yoga Sutra firmly rooted in the dualism of Samkhya philosophy
4.2 Patanjali's Eightfold path of Yoga
4.2.1 Yama (social restraints/ethical values)
4.2.2 Niyama (personal observances/ethical values)
4.2.3 Asana (posture)
4.2.4 Pranayama (breath control/regulation)
4.2.5 Pratyahara (sense withdrawal)
4.2.6 Dharana (concentration)
4.2.7 Dhyana (meditation)
4.2.8 Samadhi (ecstasy)
4.3 The goal of Raja Yoga is the attainment of a stable mind in a healthy body which then will lead to freedom (4:26, 4:36)

5   POSTCLASSICAL PERIOD
5.1 non dualistic traditions subsequent to Patanjali
>5.1.1 The one thing both mainstream and new-age post-classical philosophers had in common was their rejection of Patanjali's dualistic world view
5.1.2 Understanding the concepts of duality (dvaita) and nonduality (advaita) is no easy task
5.2 Putting a precise date on the decline of classical yoga, as represented by Patanjali, and the subsequent start of the post-classical period is impossible
5.2.1 Certain concepts and tenets from Patanjali and the early Upanishads continue unchanged or only slightly modified throughout the post-classical period