The earliest evidence for prehistoric religion in India date back to the late Neolithic in the early Harappan
period (55002600 BCE).[15][16] The beliefs and practices of the pre-classical era (1500500 BCE) are called the "historical Vedic religion". The Vedic religion shows influence from Proto-Indo-European religion.[17][18][19][20] The oldest Veda is the Rigveda, dated to 1700 1100 BCE.[21] The Vedas center on worship of deities such as Indra, Varuna and Agni, and on the Soma ritual. Fire-sacrifices, called yaja are performed by chanting Vedic mantras chanted but no temples or idols are known.[22][23] The 9th and 8th centuries BCE witnessed the composition of the earliest Upanishads.[24]:183 Upanishads form the theoretical basis of classical Hinduism and are known as Vedanta (conclusion of the Veda).[25] The older Upanishads launched attacks of increasing intensity on the rituals.[26] The diverse monistic speculations of the Upanishads were synthesized into a theistic framework by the sacred Hindu scripture Bhagavad Gita.[27] The major Sanskrit epics, Ramayana and Mahabharata, were compiled over a protracted period during the late centuries BCE and the early centuries CE.[28] They contain mythological stories about the rulers and wars of ancient India, and are interspersed with religious and philosophical treatises. The later Puranas recount tales about devas and devis, their interactions with humans and their battles against rakshasa. Increasing urbanization of India in 7th and 6th centuries BCE led to the rise of new ascetic or shramana movements which challenged the orthodoxy of rituals.[29] Mahavira (c. 549477 BCE), proponent of Jainism, and Buddha (c. 563-483), founder of Buddhism were the most prominent icons of this movement.[24]:184 Shramana gave rise to the concept of the cycle of birth and death, the concept of samsara, and the concept of liberation.[30] Radhakrishnan, Oldenberg and Neumann believed that the Buddhist canon had been influenced by Upanishads.[31] In early centuries CE several schools of Hindu philosophy were formally codified, including Samkhya, Yoga, Nyaya, Vaisheshika, Purva-Mimamsa and Vedanta.[32] The period between 5th and 9th century CE was a brilliant era in the development of Indian philosophy as Hindu and Buddhist philosophies flourished side by side.[33] Of these various schools of thought the nondualistic Advaita Vedanta emerged as the most influential and most dominant school of philosophy.[34][35] Charvaka, the atheistic materialist school, came to the fore in North India before the eighth century CE.[36] Sanskritic culture went into decline after the end of the Gupta period. The early medieval Puranas helped establish a religious mainstream among the pre-literate tribal societies undergoing acculturation. The tenets of Brahmanic Hinduism and of the Dharmashastras underwent a radical transformation at the hands of the Purana composers, resulting in the rise of a mainstream "Hinduism" that overshadowed all earlier traditions.[37] In eighth century royal circles, the Buddha started to be replaced by Hindu gods in pujas.[38] This also was the same period of time the Buddha was made into an avatar of Vishnu.[39] Though Islam came to India in the early 7th century with the advent of Arab traders and the conquest of Sindh, it started to become a major religion during the later Muslim conquest in the Indian subcontinent.[40] During this period Buddhism declined rapidly and many Hindus were
forcibly converted to Islam.[41][42][43] Numerous Muslim rulers or their army generals such as Aurangzeb and Malik Kafur destroyed Hindu temples[44][45][46] and persecuted non-Muslims; however some, such as Akbar, were more tolerant. The 17th century Hindu Maratha Empire of India is credited for ending the Islamic Mughal rule in India.[47] and furthermore the Marathas are considered as champions of Hinduism.[48] Hinduism underwent profound changes, in large part due to the influence of the prominent teachers Ramanuja, Madhva, and Chaitanya.[40] Followers of the Bhakti movement moved away from the abstract concept of Brahman, which the philosopher Adi Shankara consolidated a few centuries before, with emotional, passionate devotion towards the more accessible Avatars, especially Krishna and Rama.[49] Indology as an academic discipline of studying Indian culture from a European perspective was established in the 19th century, led by scholars such as Max Mller and John Woodroffe. They brought Vedic, Puranic and Tantric literature and philosophy to Europe and the United States. At the same time, societies such as the Brahmo Samaj and the Theosophical Society attempted to reconcile and fuse Abrahamic and Dharmic philosophies, endeavouring to institute societal reform. This period saw the emergence of movements which, while highly innovative, were rooted in indigenous tradition. They were based on the personalities and teachings of individuals, as with Ramakrishna and Ramana Maharshi. Prominent Hindu philosophers, including Aurobindo and Prabhupada (founder of ISKCON), translated, reformulated and presented Hinduism's foundational texts for contemporary audiences in new iterations, attracting followers and attention in India and abroad. Others such as Vivekananda, Paramahansa Yogananda, Sri Chinmoy, B.K.S. Iyengar and Swami Rama have also been instrumental in raising the profiles of Yoga and Vedanta in the West
