The word "India" is derived from the river Indus, along whose banks the Aryans from Central Asia came down over the Himalayas and into the Indo-Gangetic plain around 1500 BCE. However, the first evidence of human settlement in the Indian sub-continent dates back to 6000 BCE, and these settlements expanded around 3000 BCE into what is today known as the Indus valley civilization, which apparently flourished till the coming of the Aryans. Available archaeological evidence is insufficient, and the Indus script yet un-deciphered, to enable a detailed account of this period in Indian history, but there is enough to show that the Indus valley civilization was highly urbanized, based on agriculture and commerce, trading with contemporary Mesopotamian and Egyptian cities.

History cannot yet say exactly why the Indus Valley Civilization disappeared as completely as it did, with the early Aryans leading a pastoral, nomadic existence in which no trace of urban life appears. As time went by, the Aryans also metamorphosed into an urbanized culture, spreading ever southwards, and the social, economic and political change involved is depicted in the two great epics of India, the Ramayana and the Mahabharata. The old Vedic religion, naturalistic and sacrificial, gave way to the pragmatism of the Upanishads, and this in turn stimulated the rise of reformers like Vardhaman Mahavira and Gautama Buddha around the 5th century BCE, whose followers converted the attempts to reform Hinduism into the separate religions of Jainism and Buddhism respectively.

The history of India is the history of the rise and fall of many empires, some indigenous, some established by invaders who came to conquer and ended by being absorbed into the Indian mainstream, contributing to the diversity of Indian culture today. The empires mentioned in the Epics were centered around today's Delhi, but as the Aryans colonized more of the sub-continent, the centre of power shifted 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 (3rd century BCE) who stopped Alexander the Great from entering the Gangetic plain (326 to 325 BCE), the Mauryas (2nd to 1st century BCE) whose zenith was the empire of Ashoka, and the Guptas (4th century CE) in whose time Kautilya wrote the famous Arthashastra, or Treatise on Government. Places like Magadha or Pataliputra developed into 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 CE.

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); The Portuguese (Vasco de Gama landed at Calicut (Kozhikode) in 1498; the Dutch, the French and the British discovered the sea routes which allowed them to enter India from the sea, initially as traders and later as colonizers.

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. Virtually the only imperial invaders in Indian history not to stay and be absorbed into India, the British ruled India till 1947, when those fighting for India's independence achieved their goal, and Mahatma Gandhi was immortalized for having formulated the path of non-violent resistance.