Operations on the Northern front, East Africa, 1940 (the Sudan Campaign) in the Second World War, were conducted by the British in Sudan and the Armed Forces Command of Italian East Africa () in Eritrea and Ethiopia. On 1 June 1940, Amedeo, Duke of Aosta the Viceroy and Governor-General of the (AOI, Italian East Africa), commander in chief of the Armed Forces Command of the Royal Italian Army () and General of the Air Force (), had about and metropolitan troops (including naval and air force personnel) and by 1 August, mobilisation had increased the number to General Archibald Wavell, General Officer Commanding-in-Chief (GOC-in-C) of Middle East Command, had about at his disposal for Libya, Iraq, Syria, Iran and East Africa. About were in Egypt and were training in Palestine.
Hostilities began soon after the Italian declaration of war on 10 June 1940. On the Sudan–Eritrea and Sudan–Ethiopia borders, the Italian army captured Kassala, on 4 July, then Gallabat; Karora was occupied unopposed and Kurmuk taken on 7 July. The possibility of an Italian advance on Khartoum led the British to adopt a delaying strategy but apart from some local advances, the Italians fortified Kassala and Gallabat and made no offensive move. In August the Italians invaded British Somaliland and the British made a slow retreat to the coast then embarked for Aden, at some cost to the reputation of Wavell with the Prime Minister Winston Churchill. The British reversed their recognition of the Italian conquest of Ethiopia in the Second Italo-Ethiopian War (1935–1936) in favour of Haile Selassie, the deposed emperor. Mission 101 and Gideon Force were based in Sudan to conduct sabotage and subversion in the western Ethiopian province of Gojjam. After an abortive counter-attack at Gallabat in November, the British conducted patrols and raids against the Italians with Gazelle Force in the Mareb River/Gash River delta north of Kassala and bluffed their opponents into believing that the British had much larger forces in eastern Sudan.
The British blockade of the AOI made Aosta reluctant to deplete stocks of fuel, ammunition and spare parts after the invasion of British Somaliland was complete. With expectations that the Germans would defeat Britain before the end of 1940 and with the need to wait for the Italian invasion of Egypt (9–16 September 1940) to succeed before invading Sudan, the Italians in the AOI waited on events. British policy was to ensure the safety of shipping in the Red Sea and the Gulf of Aden and operations in East Africa were given second priority after Egypt. With reinforcements arriving from India and troops from Egypt due after Operation Compass, the British planned to invade Eritrea from Sudan on 9 February 1941. The British were forestalled by a sudden Italian retreat from Kassala on 18 January and Platt was ordered to mount a vigorous pursuit. The British invaded Eritrea and defeated the Italians at the Battle of Agordat (26–31 January 1941) which began the conquest of Eritrea; Selassie returned to Ethiopia on 20 January.
Background
On 9 May 1936, the Italian dictator, Benito Mussolini, proclaimed Italian East Africa ( (AOI Italian East Africa), formed from the colonies of Italian Eritrea and Italian Somaliland and Ethiopia, which had been occupied after the Second Italo-Ethiopian War (1935–1936). Amedeo, Duke of Aosta, was appointed the Viceroy and Governor-General of the AOI in November 1937, with headquarters in Addis Ababa, the Ethiopian capital. On 1 June 1940, as the commander in chief of (Italian East African Armed Forces Command) and (General of the Air Force), Aosta had about and metropolitan troops (including naval and air force personnel) in the AOI. (By 1 August, mobilisation had increased the number to
On 31 March 1940, Mussolini had laid down a defensive strategy against Kenya, a policy of limited offensives against Kassala and Gedaref (now Al Qadarif) in Sudan and a bigger offensive against French Somaliland to protect Eritrea. Naval forces based at Massawa were to take the offensive and the would provide air support for the ground and naval operations. On 10 June, Mussolini declared war on Britain and France, which made Egypt vulnerable to the forces in Italian Libya (, part of (ASI) and those in the AOI a menace to the British and French colonies in East Africa. Italian belligerence led to the closure of the Mediterranean to Allied merchant ships and endangered British supply routes along the coast of East Africa, the Gulf of Aden, Red Sea and the Suez Canal.
Mediterranean and Middle East
In mid-1939, General Archibald Wavell was appointed General Officer Commanding-in-Chief (GOC-in-C) of the new Middle East Command, over the Mediterranean and Middle East theatres. Wavell had about at his disposal for Libya, Iraq, Syria, Iran and East Africa, of which about 9,000 were in Sudan, 8,500 in Kenya, 1,475 in British Somaliland and 2,500 in Aden. From 1938, Major-General William Platt had been the (the , Commandant) of the Sudan Defence Force (SDF) with responsibility for the defence of Sudan, which had a frontier with Ethiopia. On 19 May 1940, the British discovered through signals intelligence that the Italian forces in the AOI had been ordered secretly to mobilise. Before the declaration of war, the British detected increases in the number of Italian troops on the Sudan border and assumed that if the Italians attacked Sudan, the objectives would be the capital Khartoum, to the west of the Eritrean frontier, Atbara, the junction of railways to Khartoum, from the border and Port Sudan, the only decent port and which had the only heavy engineering workshops in the country. The ground was arid and had no all-weather roads but in the dry weather before the monsoon in June or July, the ground was usable by motor vehicles nearly everywhere.
Ultra
The Italians in the AOI had replaced their ciphers by November 1940 but by the end of the month, the Government Code and Cypher School (GC&CS) in England and the Cipher Bureau Middle East (CBME) in Cairo had broken the and replacement codes. Sufficient low-grade ciphers had been broken to reveal the Italian order of battle and the supply situation, by the time that the British offensive began on 19 January 1941. Italian dependence on wireless communication, using frequencies on which it was easy for the British to eavesdrop, led to a flood of information from the daily report from the Viceroy to the operational plans of the and . On occasion, British commanders had messages before the recipients and it was reported later by the Deputy Director Military Intelligence in Cairo, that
Prelude
Anglo-Egyptian Sudan
In 1940, the British had three infantry battalions in Sudan and the SDF, which had 4,500 men in 21 companies, the best-equipped being Motor Machine-Gun companies, with light machine-guns mounted in vans, lorries and a few locally made armoured cars; the Sudan Horse was converting to a 3.7-inch mountain howitzer battery. Platt held Khartoum with 2nd Battalion, West Yorkshire Regiment, the 1st Battalion, Essex Regiment at Atbara and the 1st Battalion, Worcestershire Regiment at Gebeit and Port Sudan. The SDF garrisoned the frontier with the provincial police and a motley of irregular scouts, to watch, harass and delay the Italians.
Should the Italians invade, the units would converge against them, exploit distance, the inadequate roads, and supply difficulties, to impede their advance. The Royal Air Force (RAF) had three bomber squadrons, K Flight, 112 Squadron, with six Gladiator fighters at Port Sudan and 430 Flight, 47 Squadron for army co-operation. The aircraft were convenient for Port Sudan and the Red Sea but far from Kassala and Gedaref. In August, 203 Group was formed at Khartoum, to guard the eastern end of the Takoradi air route from the Gold Coast (now Ghana), with 1 (Fighter) Squadron, South African Air Force (SAAF), equipped with Gladiators.
Kassala
In 1940, Kassala was a provincial town of around 25,000 inhabitants, about from the frontier on the Mareb River/Gash River and the Sudan Railway which looped eastwards towards the border with Ethiopia. The river rose in Eritrea and flowed, full of silt, for about three months each year, which created extremely fertile land for cotton growing; the crop being exported from the railway station outside Kassala. The Italian ran from Asmara, the capital of Eritrea; after the Italians dammed the river at Tessenei to create a rival cotton growing industry and extended the road from Asmara to the Eritrea–Sudan border to transport the cotton crop, the road became an obvious route for an offensive in either direction. In July, the British found that Italian troops were assembling near Tessenei about inside the Eritrean border. The British planned to attack on 3 July but a wireless failure led to a postponement.
Around Kassala, the British had No. 5 Motor Machine-Gun Company SDF, No. 6 Mounted Infantry Company of the Eastern Arab Corps, SDF and a mounted infantry company of the Western Arab Corps SDF, from Darfur away and the local police. (No. 3 Motor Machine-Gun Company from Butana arrived at noon on 4 July.) After hostilities began on 10 June, the flew reconnaissance sorties over Sudan and bombed Kassala, Port Sudan, Atbara, Kurmuk and Gedaref. Small-arms were the only defence against air attack and civilian morale suffered but the bombing caused no military damage. The SDF patrolled frequently and raided across the Sudan–Ethiopia border around Kassala and Gallabat, causing some casualties and taking several prisoners. The Italian forces in the AOI remained passive in June but during July prepared to attack Karora, Kassala, Gallabat and Kurmuk.
Italian preparations
Before the Italian declaration of war, Mussolini intended a defensive strategy in the AOI, with tactical offensives to protect Eritrea by attacking French Somaliland (Djibouti) and conducting limited attacks on Sudan. The Italian army in the AOI had one metropolitan division and the non-divisional equivalent of two more European divisions, all short of heavy weapons and transport and seven maller colonial divisions.
The army was organised in four commands, the Northern Sector in the vicinity of Asmara, Eritrea (Lieutenant-General Luigi Frusci, of the , Governor of the Eritrea Governorate and Amhara Governorate), the Southern Sector in the Galla-Sidamo Governorate (General Pietro Gazzera), the Eastern Sector on the border with French Somaliland and British Somaliland (General Guglielmo Nasi) and the Giuba Sector (Lieutenant-General Carlo De Simone) covering southern Somalia near Kismayo, Italian Somaliland.
The had 325 aircraft in the AOI, 142 of which were in reserve (not all operational) with little prospect of more supplies of fuel, ammunition and spare parts. A force was concentrated near the Sudan border for an attack on Kassala, comprising two colonial brigades, four squadrons of cavalry, approximately 24 light tanks, medium tanks and armoured cars and ten batteries of artillery.
Operations
Capture of Kassala
Despite adopting a defensive strategy in East Africa, the Italians were interested in acquiring Kassala, to strengthen their frontier defences and as a potential starting point for an invasion of Sudan. It was also hoped that taking Kassala would boost morale among Italian troops and impress the local population. The rainy season was approaching, and once the rains began offensive operations would be impossible until the end of September, due to the lack of paved roads, leaving little time for the Italians to act. A force was assembled near the Sudan border to capture Kassala. The British were aware of its presence and had considered an attack to forestall the Italians but this was prevented by poor wireless communication.