(i) Khilafat Movement was started by Ali brothers in August 1920 for the preservation of the office of Khalifa (Caliph), the religious head of the Muslims. Gandhiji combined the Khilafat movement with the Non-Cooperation Movement as he saw in this an opportunity to unite the Hindus & the Muslims.
(ii) The Rowlatt Act, passed in March 1919 gave extraordinary powers to the British to imprison a person without trial.
(iii) There occurred at Amritsar on April 13, 1919 a terrible massacre at Jallianwala Bagh.