During the First World War, Turkey was an ally of Germany. The Indian Muslims suspected that after the war was over, great Britain would take action against Turkey. During the war, the Prime Minister of Britain, in order to gain the support of Indian Muslims, falsely assured them that Britain would not adopt the policy of revenge against Turkey.
But after the war, Britain did not keep its promise. It dismantled the administration of Turkey. Instead of appointing the Sultan of Turkey, as the Khalifa of Turkey Britain banished the Sultan and accepted the authority of Sheikh Hassan as the Khalifa. This infuriated Indian Muslims and they started the Khilafat movement.