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.