| TIME
| EVENT |
| 1757 | Nawab of Bengal loses the battle of Plassey to the British East India company- BEI Company officially starts to control and govern India |
| 1857 | Large scale rebellion by the sepoys against the British East India Company; last Indian emperor (Mughal king, Bahadur Shah Zafar captured by the British) |
| 1858 | East India company dissolved as a result of the 1857 mutiny, complete power transferred over to the British crown, to the queen |
| 1858 | Policy of annexation of princely states formally announced. Several kingdoms were under the suzerainty of British crown; British protected them as allies, each with individual sovereignty to administer |
| 1858 | Aden, lower Burma and Singapore comes under British India, |
| 1867 | Singapore detached from Indian empire |
| 1884 | Somaliland comes under British India |
| 1886 | Upper Burma comes into British India |
| 1898 | Somaliland separated from India |
| 1905 | Bengal partitioned along communal lines into East and West Bengal |
| 1935 | Government of India act came into existence; Sindh province separated from Bombay |
| 1937 | Aden and Burma separated from India |
| 14-15 August 1947 | British India split into India, Pakistan and 568 princely states; British reneged on their support to the princely states, and ask them to join either India or Pakistan, or remain independent |
| 27 October 1947 | Kashmir accedes to India, hostilities erupt between India and Pakistan |
| January 1 1948 | Numerous princes sign a merger to join India, into the state of Orissa, Bihar and Central provinces |
| 1948 | 66 states included Baroda and Kohlapur merge into India, into Bombay. Numerous smaller states merge into Madras, East Punjab, West Bengal, Assam and United provinces. 30 princely states merge into Himachal Pradesh. 35 princely states join India and form Vindhya Pradesh |
| February 1948 | Junagadh acceded to India after being acceded to Pakistan initially |
| 17 September 1948 | Hyderabad joins India after a hostile skirmish |
| 28 May 1948 | Madhya Bharat created from 25 princely states which acceded to India |
| 15 July 1948 | Patiala and East Punjab States Union was formed when 8 princely states join India |
| 12 October 1948 | Bilaspur joins India |
| 31 December 1948 | Hostilities end between India and Pakistan, 2/5 of Kashmir under Pakistan control, the rest comes under Indian rule. The border became known as “cease-fire line”, and later termed as “line of control” |
| 30 March 1949 | Several princely states join India in Rajputana |
| May 1 1949 | Bhopal joins India |
| July 1 1949 | Cochin and Travancore join India and form the state of Travancore-Cochin |
| 9 September 1949 | Tripura joins India |
| October 1949 | Manipur joins India |
| 1947-1950 | Vast majority of princely states joins India |
| 26 January 1950 | India becomes a republic, constitution drafted |
| 2 May 1950 | Chandranagore changes hands from France to India |
| 1 November 1954 | de facto control of Yanam, Pondicherry, Karaikal and Mahe conceded by France to India |
| July 1954 | Uprising in Dadra and Nagar Haveli throws off Portuguese rule |
| 1 November 1956 | Madhya Pradesh formed from the states of Vindhya Pradesh, Bhopal and Madhya Bharat |
| 1 November 1956 | Kutch, Vidarbha, Marathwada, Saurashtra joins Bombay state |
| 1 November 1956 | State of Mysore created from Coorg, Mysore and the kannada speaking regions of Hyderabad state; renamed Karnataka in 1973 |
| 1 November 1956 | Telugu speaking areas of Andhra state, and Telengana region of Hyderabad state merges to form Andhra Pradesh |
| 1 November 1956 | Ajmer-Merwara joins Rajaputna, renamed into Rajasthan |
| 1 November 1956 | Formation of Assam, Jammu & Kashmir, West Bengal, Uttar Pradesh, Bihar |
| 1 November 1956 | Punjab formed by the merger of the Patiala and East Punjab States Union |
| 1 November 1956 | Malabar splits from Madras state, and southern Travancore joins Madras state; Madras renamed into Tamil Nadu in 1969 |
| 1 November 1956 | 7 union territories (Manipur, Tripura, Pondicherry, Lakshadweep, Himachal Pradesh, Delhi and Andaman & Nicobar islands) formed |
| 1 November 1956 | Kerala formed from Malabar, and Travancore-Cochin state |
| 1 May 1960 | Bombay state partitioned into Maharashtra and Gujarat |
| 19 December 1961 | Portuguese surrender to Indian army; Goa, Daman and Diu merge with India |
| 21 November 1962 | Sino-Indian war ends, Aksar Chin region of Kashmir comes under Chinese control, with a de facto line of actual control separating Indian and Chinese rule |
| 1 December 1963 | Nagaland made into a separate state |
| 1 November 1966 | Haryana formed; northern districts of Punjab transferred to Himachal Pradesh |
| 25 January 1971 | Statehood conferred upon Himachal Pradesh |
| 21 January 1972 | Manipur, Meghalaya and Tripura become states of India |
| 16 May 1975 | Sikkim merges with India; becomes a separate state |
| 20 February 1987 | Arunachal Pradesh and Mizoram gains statehood |
| 30 May 1987 | Goa becomes a state of India, Daman and Diu become union territories |
| 1 November 2000 | 16 districts of Madhya Pradesh form a separate state, Chhattisgarh |
| 9 November 2000 | Uttaranchal formed out of Uttar Pradesh, renamed Uttarakhand in January 2007 |
| 15 November 2000 | Jharkhand formed out of Bihar |