India celebrates December 16 as "Vijay Diwas" commemorating Indian forces resounding victory over Pakistan in the 1971 war which led to the creation of Bangladesh.
The Pakistan army surrendered to Indian forces unconditionally when General Amir Abdullah Khan Niazi with 93,000 troops surrendered to India. The war lasted just 13 days from December 4 to 16.
It is also known as the Bangladesh Liberation War, 1971.
Indian forces enter Dhaka
Indian troops hailed as liberators as they enter Dhaka, then east Pakistan, during India and Pakistan's third major conflict in December 1971.
India's Field Marshal Sam Manekshaw told the Pakistani general explicitly "You surrender or we wipe you out" on December 13 as Pakistan Army crumbled due to India's sustained ground and air assault in the western and eastern front.
On 14 December, IAF attacked a house where a meeting was taking place of the governor of east Pakistan. The Indian Army captured Bogra, Sylhet Railway Station, Pubail & Rupganj.
Brigadier Usman, commander 50 PARA Brigade launched operations for clearing the enemy from Kot and captured Chingas on the road to Rajouri as the Indian army vanquished Pakistan.
The seeds of war
On December 12, the Indian Army captured Hardinge bridge, Khetlal & Madhupur. Narsingdi was built as a base to capture Dhaka.
The 1971 Indo-Pak conflict started when the Pak army conducted a widespread genocide against the Bengali population of the then east Pakistan.
PM Indira Gandhi expressed full support of her government for the independence struggle of the people of east Pakistan and decided to go to war against Pakistan after India's neighbour attacked.
During the war, the main Indian objective on the eastern front was to capture Dhaka and on the western front was to prevent Pakistan from entering India.
Fall of Dhaka
While India's grip on east Pakistan tightened, the IAF continued to press home attacks against Pakistan. The campaign then developed into a series of daylight anti-airfield, anti-radar and close-support attacks by fighters.
Hostilities officially ended on December 17 after the fall of Dhaka on December 15. India claimed large gains of territory in west Pakistan and the independence of Pakistan's eastern wing as Bangladesh was confirmed.
Instrument of surrender
On the ground, Pakistan suffered the most with 8,000 killed and 25,000 wounded while India lost 3,000 and 12,000 were wounded. The loss of armoured vehicles was similarly imbalanced. It was a major defeat for Pakistan.
The "Instrument of Surrender" of Pakistani forces stationed in east Pakistan was signed at the Ramna Race Course in what is now Dhaka on December 16, 1971 by Lt Gen Niazi of Pakistan and Lt Gen Aurora of India.
Pakistan loses eastern half in 1971
For Pakistan, it was a complete and humiliating defeat, a psychological setback that came from a defeat at the hands of intense rival India.
Bangladesh became an independent nation, the world's fourth most populous Muslim state. Mujibur Rahman was released from a west Pakistani prison and he returned to Dhaka on January 10, 1972 and became the first President of Bangladesh.
Karachi harbour hit
The Indo-Pakistan war of 1971 was a military confrontation and possibly one of the shortest but the most significant wars in the history of the two countries which took place in the liberation war in east Pakistan.
The war was led to the humiliating partition of Pakistan's eastern sector - Bangladesh.
The Indian Navy too did its part in the first day of the war as it attacked the Karachi Harbour.
In a 90 minute operation, it hit the Pakistani Navy headquarters as well as oil storage - killing over 5 Pakistani navel representatives and injuring over 700 men, destroying a minesweeper, a destroyer, a cargo vessel carrying ammunition, and fuel storage tanks as well as another destroyer which was heavily damaged and eventually discarded.
After destroying the Pakistani destroyer - PNS Khaibar, MV Venus Challenger, PNS Shah Jahan, and PNS Muhafiz, the fleet was only 26 kilometres away from the Karachi port when it decided to attack the oil tanks and refineries - accomplishing the operation trident with full success. After which the fleet withdrew towards Bombay.