Following the defeat of the Turkish Ottoman Empire in the First World War there was concern among Muslims everywhere for the safety of the holy places of Islam and the future of the Sultan who was also a religious head (Caliph or khalifa). The British at first gave assurances that the caliphate would be protected but later reneged on their promise. Muslims in India, led by the Ali brothers, Mohammad and Shaukat, launched an agitation to arouse world opinion against the harsh treatment of the Caliph and when they asked Gandhiji for support Gandhiji espoused their cause.
Gandhiji had always maintained that Hindus and Muslims should live in friendship and help each other. He took the view that if the Muslims were agitated about the plight of the caliphate, Hindus should not remain mute spectators. They and the whole country should take up the question of the future of the caliphate and express solidarity with their Muslim brethren. To this end he launched the non-co-operation movement. The Congress endorsed the call for non-co-operation with the government, at its Nagpur session in 1920 and declared 'Swaraj' as its goal.
What did 'Swaraj' mean?
"Self rule within the empire if possible," explained Gandhi," or outside it, if necessary."
Thus Gandhi united the whole country in the demand for Swaraj. Hindus and Muslims jointly and wholeheartedly participated in the non-violent movement.
Non-co-operation meant boycotting everything that was British — goods, educational institutions, legislatures, law-courts, jobs and honours. It meant using home-spun khadi, attending national schools, settling disputes out of court, generating jobs outside the government and, ultimately, refraining from paying taxes. Simply put, it meant that Indians would cease to recognize the British as their rulers and would behave like free people.
The positive outcome of the non-co-operation movement was self-reliance.
Responding to Gandhi's call, students walked out of schools and colleges run by the government and enrolled in educational institutions run by patriotic non-governmental bodies. 800 such institutions had been started in various parts of the country. In Bengal, the managements of hundreds of schools and some colleges were pressurised by their students to disassociate the school or college from government institutions.
Subhas Chandra Bose became principal of the National College in Calcutta.