On that date in 1971, Sheikh Mujibur Rahman signed a declaration making East Pakistan the sovereign and independent country of Bangladesh
It sparked the nine-month long Bangladesh Liberation War which claimed the lived of between 300,000 to 3 million people, although the casualty figures are disputed. Millions more were displaced.
Towards the end of the war, India invaded East Pakistan in support of the East Pakistani people and their forces.
This led more than 93,000 Pakistani troops to surrender – the largest number since World War II.
On 16 December 1971, East Pakistan officially became the independent country of Bangladesh.
Google are marking the national holiday with a doodle, which features an illustration of men in boats, nodding to Bangladesh’s many rivers.
Bangladesh Independence Day is marked in the country with parades, concerts and often speeches.
In the capital city of Dhaka, many government buildings are lit up in red and green, the national colours.
As the two colours that make up the national flag, the green symbolises Bangladesh’s flora and the red circle represents the sun rising over the relatively new country.