India on Wednesday is observing the 50th anniversary of the 1971 war with Pakistan, also known as the Bangladesh Liberation War. Fought under the leadership of then-prime minister Indira Gandhi and chief of army staff (COAS), General Sam Manekshaw, the war ended in less than two weeks with a decisive victory for India, and resulted in the creation of Bangladesh, which was then known as East Pakistan.

Here’s all you need to know about the 1971 India-Pakistan war:

1. The conflict took place in the backdrop of tensions between Pakistan (also known then as West Pakistan) and the Bengali majority East Pakistan, which was closer to India then it was to Pakistan.

2. On 25 March 1971, the Pakistan Army, led by Lieutenant General Tikka Khan, who later went on to become Pakistan’s first COAS, launched Operation Searchlight to quell the rebellion in East Pakistan. Massive human rights violations were reportedly perpetrated by the Pakistan Army during this operation.

3. The hostilities between India and Pakistan formally began on December 3, 1971, when the Pakistan Air Force (PAF), launched pre-emptive air strikes on 11 Indian airfields. Addressing the nation the same evening, PM Indira Gandhi called the air strikes “declaration of war against India.”

4. While the Indian Air Force (IAF) responded with initial retaliatory strikes the same night, PM Gandhi ordered a “full-scale” invasion of Pakistan. Thus officially commenced the Indo-Pakistani war of 1971.

5. The war came to an end in less than two weeks on December 16, 1971, with the Eastern Command chief of the Indian Army, Lt Gen JS Aurora, making the Eastern Command chief of the Pakistan Army, Lt Gen AAK Niazi, sign the instrument of surrender.

6. As a result of the surrender, around 93,000 Pakistani troops were taken as prisoners of war (PoW) by India. The 13-day duration of the war also makes it one of the shortest wars in history.

7. East Pakistan became Bangladesh, with Awami League leader, Sheikh Mujibur Rahman, becoming its first President in January 1972, as well as its second prime minister in 1974. Mujib, who was assassinated in 1975, is the father of current Bangladesh PM Sheikh Hasina.

8. The war is also known for the Indian Navy’s daring assault, called Operation Trident, on Pakistan’s financial hub of Karachi, which was also the headquarters of the Pakistan Navy. To commemorate this operation, India observes December 4 as Navy Day.

9. The 1971 war is also known for the battle of Longewala, in Rajasthan, in which outnumbered Indian troops fought off advancing Pakistani adversaries. The battle is the subject of the 1997 Bollywood film ‘Border,’ with actor Sunny Deol playing Major KS Chandpuri, who led Indian troops

10. Throughout the conflict, the Indian forces were assisted by the Mukti Bahini, a Bengali guerrilla resistance movement, which was fighting the Pakistani forces.