India is the oldest continuous living civilization in the world.  Archaeological studies have shown that there is a continuity in Indian civilization that goes back to at least 8000 B.C.  DNA studies from the Rakhigarhi excavations in Haryana, which is the largest site of the Harappan Civilization located almost in the middle of the Saraswati river basin in the Indus Valley Civilization,  have shown that the site was under occupation from Early Harappan (5500 BCE-2600 BCE) to  Mature Harappan (2600 BCE-1900 BCE)  period. The Indian rock art has even longer prehistory; several rock paintings sites in India are estimated to be about 40,000-10000 years old.  The Advisory Body Evaluation (ICOMOS) report of UNESCO for Rock shelters of Bhimbetka (cave paintings) in India, which is a UNESCO world heritage site, states that in at least one of the excavated shelters, it is said in the nomination that continued occupation is demonstrable from 100,000 BCE (Late Acheulian) to 1000 AD. 

The Indus Valley Civilization, which was initially thought to consist of cities based along the Indus River, is now thought to have been located in a much wider area. This is due to a number of new sites discovered in recent years far away from the Indus River. The location of new sites along a dried up river bed, much wider than the present stream in that region, alongwith other multi-disciplinary research has given credence to the theory of a lost mega river, Saraswati, which is described in the Rigveda (the oldest book in the human library) as a large river of the Vedic Civilization.

The Indus Valley Civilization was one of the first large-scale urban societies of the ancient world, characterized by systematic town planning, elaborate drainage systems, granaries and standardization of weights and measures. The inhabitants of this civilization were cosmopolitan, with inhabinants living together in large regional urban centers like Harappa (Punjab), Mohenjodaro (Sindh), Rakhigarhi (Haryana), Dholavira (Kutch/Gujarat), and Ganweriwala (Cholistan). The mounds of Bhirrana village on the banks of Ghaggar river in Fatehabad district of Haryana date back to 7500-6200 BCE and are considered to be the oldest Harappan site.   Recent DNA studies from Rakhigarhi  site  have set aside the earlier hypothesis about mass human migration/Aryan migration from outside the South Asia and establish that the hunter gatherers in Indian sub continent have independent origin, that the people of the Harappan Culture are the ancestors of the most of the population of South Asia and give rise to a new Out of India hypotheses implying that there was a movement of the people from South Asia to West bringing with them the Indian languages.  The Harappan people’s presence is evident at sites like Gonur in Turkmenistan and Sahr-i-Sokhta in Iran. The Vedic civilization, the time when Vedas were composed, is thought to be the same as the Harappan Civilization.

At the time when Harappan Culture was thriving,  other parts of the Indian sub continent were inhabited too.  Sanauli burial sites in the Uttar Pradesh state of India have yielded chariots engraved with copper, and are estimated to be about 4000 years old. Keeladi excavations in Tamil Nadu, a state in south of India, are estimated to be from 6^th century BCE and suggest that the urbanisation of Vaigai plains happened in Tamil Nadu around the same time as the Gangetic plains.

History cannot yet say exactly why the Harappan culture disappeared, however experts are coming around to the view that the drying of ‘lost’ Saraswati river, the preeminent river of Rig-Vedic times,  as a result of tectonic upheavals led to gradual shifting away of inhabitants from these cities  along the river.  Around 6^th Century BCE, great philosophers  like Vardhaman Mahavira and Gautama Buddha  captivated India with their teachings, whose followers converted their thoughts into the separate religions of Jainism and Buddhism respectively.

The history of India is the history of the rise and fall of many empires, most indigenous, some established by invaders who came to conquer and ended up being absorbed into the Indian mainstream, contributing to the diversity of Indian culture today. The empires mentioned in the Epics like Ramayana and Mahabharata were centred in the North of India and the capitals of the great dynastic empires of ancient India were in the area today covered by the state of Bihar. These dynasties included the Nandas (3nd century BC) who stopped Alexander the Great from entering the Gangetic plain (326-325 BC), the Mauryas (2nd – 1st century BC) whose zenith was the empire of Ashoka, and the Guptas (4th century AD) in whose time Kautilya wrote the famous Arthshastra. Cities like Magadha and Pataliputra were developed, prosperous centres of commerce, culture and learning, and their fame spread far and wide.   The last great empire in this period of Indian history was that of Harsha in the 7th century AD.     India was the centre of learning in the world as students from many countries flocked to the famed universities like Nalanda, Vikramshila and Taxila.  

At the same time, the glory of India’s cultural and civilizational treasures were nurtured and spread across much of South East Asia and South Asia by the empires in the south of India.  Prominent among these empires included the Vijayanagara empire, Chola (300 BCE-1279 CE.  One of the longest ruling dynasties in the world’s history. During the reign of Rajaraja Chola I and his successor Rajendra Chola I,  the Chola navy dominated  a large part of Southeast Asia),  Pandyan, Chera, etc.

The heyday of invasions was in what is today classified as Medieval India, when the Turks and the Mongols penetrated into India from the North in waves beginning in the 11th century which ultimately culminated in the establishment of the Mughal empire (1526 to 1857), and the Portuguese (Vasco de Gama landed at Calicut (Kozhikode) in 1498 with the help of an Indian trader who brought him to India from the eastern seaboard of Africa), the Dutch, the French and the British followed using the sea routes which allowed them to enter India, initially as traders and later as colonisers.

The British overcame indigenous resistance (beginning with the Battle of Plassey in 1757) and French competition (the first Anglo-French war was fought in 1748) to annex most of India, especially after the end of the First War of Independence in 1857 when the British Crown took over the government of British India from the East India Company. The British ruled India till 1947, when those fighting for India’s independence achieved their goal, and Mahatma Gandhi was immortalised for having formulated the path of non-violent resistance.