Bangladesh: Forty years of independence
16 December 2011 Last updated at 13:49 GMT
After a war lasting nine months and with the aid of India, East Pakistan seceded from West Pakistan and became the independent state of Bangladesh on 16 December 1971.
The country did not have a very auspicious beginning.
The war had left three million people dead and a further 10 million displaced in India.
There soon followed a great famine which claimed at least another one million lives.
The BBC's Anbarasan Ethirajan reports from Dhaka.