Most of the Indian subcontinent was conquered by the Mauryan Empire during the 4th and 3rd centuries BCE. From the 3rd century BCE onwards Prakrit and Pali literature in the north and the Tamil Sangam literature in southern India started to flourish. Wootz steel originated in south India in the 3rd century BCE and was exported. The Mauryan Empire would collapse in 1185 BCE, on the assassination of the Emperor at that point, Brihadratha, by his General Pushyamitra Shunga. Who would go on to for the Shunga Empire, in the North and North East of the subcontinent, while the Greco-Bactrian Kingdom would claim the North West, and found the Indo-Greek Kingdom. During this Classical period, various parts of India were ruled by numerous dynasties, including the 4-6th centuries CE Gupta Empire. This period, witnessing a Hindu religious and intellectual resurgence, is known as the classical or “Golden Age of India”. During this period, aspects of Indian civilization, administration, culture, and religion (Hinduism and Buddhism) spread to much of Asia, while kingdoms in southern India had maritime business links with the Middle East and he Mediterranean. Indian cultural influence spread over many parts of Southeast Asia, which led to the establishment of Indianised kingdoms in Southeast Asia (Greater India).

The most significant event between the 7th and 11th century was the Tripartite struggle centered on Kannauj that lasted for more than two centuries between the Pala Empire, Rashtrakuta Empire, and Gurjara-Pratihara Empire. Southern India saw the rise of multiple imperial powers from the middle of the fifth century, most notably the Chalukya, Chola, Pallava, Chera, Pandyan, and Western Chalukya Empires. The Chola dynasty conquered southern India and successfully invaded parts of Southeast Asia, Sri Lanka, the Maldives, and in the 11th century. In the early medieval period Indian mathematics, including Hindu numerals, influenced the development of mathematics and astronomy in the Arab world.

Islamic conquests made limited inroads into modern Afghanistan and Sindh as early as the 8th century, followed by the invasions of Mahmud Ghazni. The Delhi Sultanate was founded in 1206 CE by Central Asian Turks who ruled a major part of the northern Indian subcontinent in the early 14th century, but declined in the late 14th century,[19] and saw the advent of the Deccan sultanates. The wealthy Bengal Sultanate also emerged as a major power, lasting over three centuries. This period also saw the emergence of several powerful Hindu states, notably Vijayanagara and Rajput states, such as Mewar. The 15th century saw the advent of Sikhism. The early modern period began in the 16th century, when the Mughal Empire conquered most of the Indian subcontinent, signaling the proto-industrialization, becoming the biggest global economy and manufacturing power, with a nominal GDP, that valued a quarter of world GDP, superior than the combination of Europe’s GDP. The Mughals suffered a gradual decline in the early 18th century, which provided opportunities for the Marathas, Sikhs, Mysoreans, Nizams, and Nawabs of Bengal to exercise control over large regions of the Indian subcontinent.

From the mid-18th century to the mid-19th century, large regions of India were gradually annexed by the East India Company, a chartered company acting as a sovereign power on behalf of the British government. Dissatisfaction with company rule in India led to the Indian Rebellion of 1857, which rocked parts of north and central India, and led to the dissolution of the company. India was afterwards ruled directly by the British Crown, in the British Raj. After World War I, a nationwide struggle for independence was launched by the Indian National Congress, led by Mahatma Gandhi, and noted for nonviolence. Later, the All-India Muslim League would advocate for a separate Muslim-majority nation state. The British Indian Empire was partitioned.

Jawaharlal Nehru, the first prime minister of India, often regarded as the architect of modern India, addressing a newly independent India on August 15, 1947.

The history of independent India began when the country became an independent nation within the British Commonwealth on 15 August 1947. Direct administration by the British, which began in 1858, affected a political and economic unification of the subcontinent. When British rule came to an end in 1947, the subcontinent was partitioned along religious lines into two separate countries—India, with a majority of Hindus, and Pakistan, with a majority of Muslims. Concurrently the Muslim-majority northwest and east of British India was separated into the Dominion of Pakistan, by the partition of India. The partition led to a population transfer of more than 10 million people between India and Pakistan and the death of about one million people. Indian National Congress leader Jawaharlal Nehru became the first Prime Minister of India, but the leader most associated with the independence struggle, Mahatma Gandhi, accepted no office. The Constitution adopted in 1950 made India a democratic country, and this democracy has been sustained since then. India’s sustained democratic freedoms are unique among the world’s newly independent states.

The nation has faced religious violence, casteism, naxalism, terrorism and regional separatist insurgencies. India has unresolved territorial disputes with China which in 1962 escalated into the Sino-Indian War, and with Pakistan which resulted in wars in 1947, 1965, 1971 and 1999. India was neutral in the Cold War, and was a leader in the Non-Aligned Movement. However, it made a loose alliance with the Soviet Union from 1971, when Pakistan was allied with the United States and the People’s Republic of China.

India is a nuclear-weapon state, having conducted its first nuclear test in 1974, followed by another five tests in 1998. From the 1950s to the 1980s, India followed socialist-inspired policies. The economy was influenced by extensive regulation, protectionism and public ownership, leading to pervasive corruption and slow economic growth. Beginning in 1991, neoliberal economic reforms have transformed India into the third largest and one of the fastest-growing economies in the world. From being a relatively destitute country in its formative years,[3] the Republic of India has emerged as a fast growing G20 major economy with high military spending, and is seeking a permanent seat in the United Nations Security Council.

India has sometimes been referred to as a great power and a potential superpower given its large and growing economy, military and population.

Independent India’s first years were marked with turbulent events—a massive exchange of population with Pakistan, the Indo-Pakistani War of 1947 and the integration of over 500 princely states to form a united nation. Credit for the political integration of India is largely attributed to Vallabhbhai Patel (deputy Prime Minister of India at the time), who (post-independence and before the death of Mahatma Gandhi) teamed up with Jawaharlal Nehru and Gandhi to ensure that the constitution of independent India would be secular.

British India consisted of 17 provinces and 565 princely states. The provinces were given to India or Pakistan, in some cases in particular—Punjab and Bengal—after being partitioned. The princes of the princely states, however, were given the right to either remain independent or join either dominion. Thus India’s leaders were faced with the prospect of inheriting a fragmented nation with independent provinces and kingdoms dispersed across the mainland. Under the leadership of Sardar Vallabhbhai Patel, the new Government of India employed political negotiations backed with the option (and, on several occasions, the use) of the military action to ensure the primacy of the central government and of the Constitution then being drafted. Sardar Patel and V. P. Menon convinced the rulers of princely states contiguous to India to accede to India. Many rights and privileges of the rulers of the princely states, especially their personal estates and privy purses, were guaranteed to convince them to accede. Some of them were made Rajpramukh (governor) and Uprajpramukh (deputy governor) of the merged states. Many small princely states were merged to form viable administrative states such as Saurashra, PEPSU, Vindhya Pradesh and Madhya Bharat. Some princely states such as Tripura and Manipur acceded later in 1949.

There were three states that proved more difficult to integrate than others:

• Junagadh (Hindu-majority state with a Muslim Nawaz)—a December 1947 plebiscite resulted in a 99% vote⦁ [15] to merge with India, annulling the controversial accession to Pakistan, which was made by the Nawab against the wishes of the people of the state who were overwhelmingly Hindu and despite Junagadh not being contiguous with Pakistan.
• Hyderabad (Hindu-majority state with a Muslim nizam)—Patel ordered the Indian army to depose the government of the Nizam, code-named Operation Polo, after the failure of negotiations, which was done between 13 and 29 September 1948. It was incorporated as a state of India the next year.
• The area of Kashmir (Muslim-majority state with a Hindu king) in the far north of the subcontinent quickly became a source of controversy that erupted into the First Indo-Pakistani War which lasted from 1947 to 1949. Eventually, a United Nations-overseen ceasefire was agreed that left India in control of two-thirds of the contested region. Jawaharlal Nehru initially agreed to Mountbatten’s proposal that a plebiscite be held in the entire state as soon as hostilities ceased, and an UN-sponsored cease-fire was agreed to by both parties on 1 Jan. 1949. No statewide plebiscite was held, however, for in 1954, after Pakistan began to receive arms from the United States, Nehru withdrew his support. The Indian Constitution came into force in Kashmir on 26 January 1950 with special clauses for the state.

The Constituent Assembly adopted the Constitution of India, drafted by a committee headed by Dr. B. R. Ambedkar, on 26 November 1949. India became a sovereign democratic republic after its constitution came into effect on 26 January 1950. Dr. Rajendra Prasad became the first President of India. The three words ‘socialist’, ‘secular’ and ‘integrity’ were added later with the 42nd Constitution Amendment 1976.