On 1 April 1941, pro-German Rashid Ali and a group of supporters staged a "coup d'état" to depose the government of the pro-British Regent of the Kingdom of Iraq, Prince Abdul Illah. From 2 April, Cornwallis was named as the British Ambassador to Iraq. He had much experience in Mesopotamia having spent twenty years in the country as adviser to former King Faisal I who had died in 1933. Cornwallis, being highly regarded, was sent to Iraq on the understanding that he would be able to hold a more forceful line with the new Iraqi government than had hitherto been the case. Unfortunately the British agent Cornwallis arrived in Iraq too late to prevent the outbreak of war.