[Protests and Violence] The partition of Bengal created a Muslim-majority province, the East Bengal. The elite Hindus of West Bengal, who were collecting taxes from Muslim peasants in east Bengal, would now lose their influence in the new province. They, therefore, rejected the decision and launched a series of violent protests and demonstrations against the partition. The tide of anger rapidly spread to other parts of India. The reaction was so strong that it gave birth to the development of extremism. A number of small extremist groups came into existence that launched attacks on the British officials. They succeeded in killing a few ones. Lord Minto, the future viceroy, escaped an assassination attempt. Many extremists were imprisoned for long time, but the situation was alarming to the British. Finally, they had to bow down before the Hindu agitation and thus revoked the Bengal partition.
[Economic Reasons] The British reversed the partition of Bengal due to economic reasons also. The Hindus of West Bengal started Swadeshi Movement, which also spread to other parts of India. It was a massive campaign for boycotting the British goods and using home-made products. The Hindus responded to the movement enthusiastically. The use of local products became a matter of pride. Foreign clothes were thrown on bonfires. By 1908, imports from Britain had fallen off significantly and sales of British goods in Indian markets dropped drastically. So the British had to reverse the decision.
[British Measures Failed] The British took several measures to bring the situation under control but political unrest kept on growing. Restrictions were imposed on newspapers and public gatherings. Editors were imprisoned. The prisons were filled with revolutionary activists. Tilak was also arrested in June 1908 and put behind the bars for 6 years. Apart from repressive measures, the British turned to reconciliation also by introducing Morley-Minto reforms in 1909 to win support of the Hindus, but the reforms also could not pacify them. The situation was becoming difficult for peaceful administration and ultimately the British had to move towards annulment of the partition.