The evolution of Hindu Dharma may be divided into three periods: the ancient (6500 B.C.-1000 A.D.), the medieval (1000-1800 A.D.) and the modern (1800 A.D. to the present).
The Ancient Period is characterised by the worship of Shiva (Pashupati) during the Harappan times; the composition of the early Rig Vedic hymns; the Epic Period during which the Ramayana and Mahabharata were composed; period of Sage Vishwamitra, in whose reign a majority of the Vedic hymns were composed; the Yajurveda and Atharvaveda were composed around 2400 B.C.; the ‘Bhagwad Gita’ was compiled between 500-200 B.C.; ‘Nyaya’, ‘Sankhya’ and the ‘Brahma Sutras’ were recorded, which later gave birth to six popular schools of the Hindu philosophy and final versions of the Puranas, Tantras and other sectarian literature were developed (200-750 A.D.). Development of the six popular schools of religious thought, establishment of Shankara’s ‘Advaita Vedanta’ and the decline of Buddhism are the main landmarks of the period 750-1000 A.D.
The Medieval Period saw the rise of devotional movements led by Ramanuja, Ramananda, Tukaram, Guru Nanak, Surdas, Chaitanya, Mirabai, Tulsi Das and many other saints.