| Alauddin Khalji conquered the throne of Delhi. In July declared himself as the Sultan. |
| 21-October-1577 |
| Guru Ramdas, Sikh Guru, established Amritsar city. |
| 21-October-1762 |
| Herman W Daendels, Brig-General and Governor General of Dutch-Indies (1807-11), was born. |
| 21-October-1789 |
| Ramshastri Prabhune, justice of Peshwa kingdom, died. |
| 21-October-1858 |
| Ramabai Dongre Medhavi, great social reformer, was born. |
| 21-October-1887 |
| Dr. Sri Krishna Sinha, great politician, revolutionist leader and chief minister, was born at Khanwa. |
| 21-October-1906 |
| Gandhiji went to England till Nov 30 on deputation to present Indians' case to Colonial Secretary. |
| 21-October-1916 |
| Dinkarrai Dhirajlal Desai, cricket Test Umpire for 3 tests from 1955-57, was born in Gujarat. |
| 21-October-1934 |
| Loknayak Jayprakash Narayan and his friends established the 'Congress Socialist Party' and Acharya Narendra Dev was its President and JP was its Gen. Secretary. |
| 21-October-1943 |
| Azad Hind Government was established in Singapore and Netaji Subhashchandra Bose was elected as its national leader. |
| 21-October-1947 |
| The office of Controller of Military Accounts (Pensions), Lahore was bifurcated and the pension work relating to Indian nationals was transferred to Allahabad. |
| 21-October-1950 |
| China invades Tibet. |
| 21-October-1954 |
| Government of India and France sign an agreement for the de-facto transfer of the French settlement of Pondicherry, Karaikal, Mahe to the Indian Union. The merger took place on November 1. |
| 21-October-1959 |
| Chinese and Indian troops clash on Ladakh border. |
| 21-October-1981 |
| Kerala under central rule. |
| 21-October-1989 |
| Sukhdev Singh alias Sukha and Harminder Singh alias Jinda sentenced to death for the murder of former Army Chief Gen. A. K. Vaidya. |
| 21-October-1990 |
| Doordarshan starts afternoon news bulletins at 2 p.m. (Hindi) and 3 p.m. (English) of 7.5 minutes duration on week days and 5 minutes on Sundays. |
| 21-October-1994 |
| Government notifies substantial increase in the ceiling on election expenses on Lok Sabha and Assembly polls. |
| 21-October-1995 |
| L.K.Advani unanimously re-elected BJP president for the fourth time in New Delhi. |
| 21-October-1995 |
| Suresh Mehta, Finance Minister in the outgoing Keshubhai Patel ministry, sworn in as the second BJP CM of Gujarat in Gandhinagar, ending the month-long political turmoil. |
| 21-October-1996 |
| Japan gets non-permanent seat in Security Council after a contest with India. |
| 21-October-1997 |
| Himachal Pradesh Assembly goes global with inauguration of its website on the Internet. |
| 21-October-1997 |
| RBI de-regulates deposit rates, reduces CRR and Bank Rate (from 10\% to 9) and allows banks to have two sets of Prime Lending Rates. |
| 21-October-1998 |
| Ajit alias Hamid Ali Khan (76), Hindi film actor, dies in Hyderabad. |
| 21-October-1999 |
| B. R. Chopra, filmmaker, gets the Dadasaheb Phalke Award. |
| 21-October-1999 |
| Madhavrao Scindia becomes the Deputy Leader of Congress (I) in the Lok Sabha. |
| 21-October-2000 |
| Seema Antil becomes the first Indian ever to win a global title by bagging a gold medal in disc throw in the World Junior Athletic championship in Santiago. |