Why was Bangladesh formed?

Bangladesh, Pakistan and India were all one country before, India. However, religious tensions between Hindus and Muslims caused Pakistan to secede from India, with Bangladesh also part of the new country as East Pakistan. Many Muslims from the state of Bihar in India also fled to Bangladesh. Next, racial tensions arose between the Urdu-speaking Pakistanis & Biharis, and the Bengalis in East Pakistan. This resulted in a fight for Independence, where East Pakistan became Bangladesh in 1971.