Because imperial metropoles displayed a sense of weakness and needed the help of the countries they ruled, the First World War brought about a temporary reversal in the relations between imperial metropoles and colonial possessions. As a result, colonial subjection was shaken. The case of the Nile Valley is very interesting from this point of view: there is successively a growing British request, an Egyptian reaction at the end of the war, and soon after a counter reaction of British authorities southwards.We will study the impact of WWI on Egypt that determined the claim for independence as soon as the military conflict ended. In order to curb the spreading of nationalist ideas through Sudan, the British General Governor of Sudan worked out a scheme for separating Egypt and Sudan. This study stresses the link between the developments in Egypt and in Sudan after WWI. The Sudanese crisis of 1924, and particularly the British firmness, is closely connected to the Egyptian political changes that occurred at the end of the war. French diplomatic archives give a very interesting and not yet explored point of view on these events.