February 21 in History
1952 – The Bengali Language Movement protests occur at the University of Dhaka in East Pakistan (now Bangladesh)
In 1948, the Government of the Dominion of Pakistan, composed of various ethnic and linguistic groups, with the geographically non-contiguous East Bengal province having a mainly Bengali population, ordained Urdu as the sole national language, sparking extensive protests among the Bengali-speaking majority of East Bengal. Facing rising sectarian tensions and mass discontent with the new law, the government outlawed public meetings and rallies. The students of the University of Dhaka and other political activists defied the law and organized a protest on this day in 1952. The movement reached its climax when police killed student demonstrators on that day. The deaths provoked widespread civil unrest. After years of conflict, the central government relented and granted official status to the Bengali language in 1956.
The Language Movement catalyzed the assertion of Bengali national identity in East Bengal and later East Pakistan, and became a forerunner to Bengali nationalist movements, including the 6-Point Movement and subsequently the Bangladesh Liberation War and the Bengali Language Implementation Act, 1987. In Bangladesh, February 21, (Ekushey February) is observed as Language Movement Day, a national holiday. In 1999, UNESCO declared this day as International Mother Language Day, in tribute to the Language Movement and the ethno-linguistic rights of people around the world.
-Wikipedia