of Egypt was retitled as the Kingdom of Egypt and Sudan, but it was Saad Zaghloul who continued to be frustrated in the ambitions until his death in 1927. From 1924 until independence in 1956, the British had a policy of running Sudan as two essentially separate territories; the north and south. The assassination of a Governor-General of Anglo-Egyptian Sudan in Cairo was the causative factor; it brought demands of the newly elected Wafd government from colonial forces. A permanent establishment of two battalions in Khartoum was renamed the Sudan Defence Force acting as under the government, replacing the former garrison of Egyptian army soldiers, saw action afterward during the Walwal Incident. The Wafdist parliamentary majority had rejected Sarwat Pasha's accommodation plan with Austen Chamberlain in London; yet Cairo still needed the money. The Sudanese Government's revenue had reached a peak in 1928 at £6.6 million, thereafter the Wafdist disruptions, and Italian borders incursions from Somaliland, London decided to reduce expenditure during the Great Depression. Cotton and gum exports were dwarfed by the necessity to import almost everything from Britain leading to a balance of payments deficit at Khartoum. In July 1936 the Liberal Constitutional leader, Muhammed Mahmoud was persuaded to bring Wafd delegates to London to sign the Anglo-Egyptian Treaty, "the beginning of a new stage in Anglo-Egyptian relations", wrote Anthony Eden. The British Army was allowed to return to Sudan to protect the Canal Zone. They were able to find training facilities, and the RAF was free to fly over Egyptian territory. It did not, however, resolve the problem of Sudan: the Sudanese Intelligentsia agitated for a return to metropolitan rule, conspiring with Germany's agents. Mussolini made it clear that he could not invade Abyssinia without first conquering Egypt and Sudan; they intended unification of Libya with Italian East Africa. The British Imperial General Staff prepared for military defence of the region, which was thin on the ground. The British ambassador blocked Italian attempts to secure a Non-Aggression Treaty with Egypt-Sudan. But Mahmoud was a supporter of the Grand Mufti of Jerusalem; the region was caught between the Empire's efforts to save the Jews, and moderate Arab calls to halt migration. The Sudanese Government was directly involved militarily in the East African Campaign. Formed in 1925, the Sudan Defence Force played an active part in responding to incursions early in World War Two. Italian troops occupied Kassala and