East African Campaign ( World War I ) The East African Campaign was a series of battles and guerrilla actions which started in German East Africa and ultimately affected portions of Mozambique , Northern Rhodesia , British East Africa , Uganda , and the Belgian Congo . The campaign was effectively ended in November 1917 . However , the Germans entered Portuguese East Africa and continued the campaign living off Portuguese supplies . The strategy of the German colonial forces , led by Lieutenant Colonel ( later " Generalmajor " ) Paul Emil von Lettow - Vorbeck , was to drain and divert forces from the Western Front to Africa . His strategy failed to achieve these results after 1916 , as mainly Indian and South African forces , which were prevented by colonial policy from deploying to Europe , conducted the rest of the campaign . Nevertheless , the Germans fought for the whole of World War I , receiving word of the armistice on 14 November 1918 at 7 : 30 a . m . Both sides waited for confirmation , and the Germans formally surrendered on 25 November . German East Africa ultimately became two League of Nations Class B Mandates , Tanganyika Territory of the United Kingdom and Ruanda - Urundi of Belgium , while the Kionga Triangle became a mandate of Portugal . Background . German East Africa ( comprising Burundi , Rwanda , and the mainland part of modern - day Tanzania ) was a large territory with complex geography , including parts of the extensive East African Rift , Lake Tanganyika and Lake Victoria . It varied from the mountainous , well - watered and fertile north - west , to the drier and sandy or rocky center , with wildlife - rich grasslands in the north - east and vast areas of uninhabited forest in the south - east . Its coast , inhabited by the Swahili people and Arab traders , dominated trade with Central Africa in conjunction with British - controlled Zanzibar and the coasts of modern - day Kenya and Mozambique . At the start of the Great War , Governor Heinrich Schnee of German East Africa ordered that no hostile action was to be taken . To the north , Governor Sir Henry Conway Belfield of British East Africa stated that he and " this colony had no interest in the present war . " The colonial governors , who often met in prewar years , had discussed these matters and wished to adhere to the Congo Act of 1885 , which called for overseas possessions to remain neutral in the event of a European war . Neither colony had many troops . In order to preserve the authority of white colonial administrators , and the concept of the inviolability of white people in general , few black soldiers were trained or maintained . It was considered dangerous to have black troops fighting against white troops , even where both sides were predominantly composed of black Africans with white European officers . As such , both the British and Germans only maintained small forces to deal with local risings and border raids . Campaign history . Beginning , 1914 – 1915 . In East Africa , the Congo Act was first broken by the British . On 5 August 1914 , troops from the Uganda protectorate assaulted German river outposts near Lake Victoria , and on 8 August a direct naval attack commenced when the Royal Navy warships and bombarded Dar es Salaam from several miles offshore . In response , the commander of the German forces in East Africa , Lieutenant Colonel Paul Emil von Lettow - Vorbeck , bypassed Governor Schnee , nominally his superior , and began to organize his troops for battle . At the time , the German " Schutztruppe " in East Africa consisted of 260 Germans of all ranks and 2 , 472 Askari , and was approximately numerically equal with the two battalions of the King ' s African Rifles ( KAR ) based in the British East African colonies . On 15 August , German Askari forces stationed in the Neu Moshi region engaged in their first offensive of the campaign . Taveta on the British side of Kilimanjaro fell to 300 askaris of two field companies with the British firing a token volley and retiring in good order . In September , the Germans began to stage raids deeper into British East Africa and Uganda . German naval power on Lake Victoria was limited to a tugboat armed with one " pom - pom " gun , causing minor damage but a great deal of news . The British then armed the Uganda Railway lake steamers , , " Winifred " and " Sybil " as improvised gunboats . Two of these trapped the tug , which the Germans scuttled . The Germans later raised her , dismounted her gun for use elsewhere and continued to use the tug as an unarmed transport . However , with the tug ’ s " " teeth removed , British command of Lake Victoria was no longer in dispute . " " In an effort to solve the raiding nuisance and to capture the entire northern , white settler region of the German colony , the British command devised a two - pronged plan . The British Indian Expeditionary Force " B " of 8 , 000 troops in two brigades would carry out an amphibious landing at Tanga on 2 November 1914 to capture the city and thereby control the Indian Ocean terminus of the Usambara Railway ( see Battle of Tanga ) . In the Kilimanjaro area , the Force " C " of 4 , 000 men in one brigade would advance from British East Africa on Neu - Moshi on 3 November 1914 to the western terminus of the railroad ( see Battle of Kilimanjaro ) . After capturing Tanga , Force " B " would rapidly move north - west , join Force " C " and mop up what remained of the broken German forces . Although outnumbered 8 : 1 at Tanga and 4 : 1 at Longido , the " Schutztruppe " under Lettow - Vorbeck prevailed . According to the British " Official History of the War " the events are described as one of " the most notable failures in British military history . " Naval war . The German naval command had just one major warship in the Indian Ocean when war was declared , the light cruiser . After limited opportunities for commerce raiding , " Königsberg " sank the cruiser HMS " Pegasus " in Zanzibar harbour and then retired into the Rufiji River delta . After being cornered by warships of the British Cape squadron , including an old battleship , two shallow - draught monitors with guns were brought from England that demolished the cruiser on 11 July 1915 . The surviving crew of " Königsberg " and her main battery guns were taken over by the " Schutztruppe " . The British salvaged and used six from the sunken " Pegasus " , the so - called ' Peggy guns ' . Lake Tanganyika expedition . In 1915 , two British motorboats , HMS " Mimi " and " Toutou " , were transported by land to the British shore of Lake Tanganyika . They captured the German ship " Kingani " , renaming it , and with two Belgian ships under the command of Commander Geoffrey Spicer - Simson , attacked and sank the German ship " Hedwig von Wissmann " in a bid to secure the lake as the strategic key to the western part of the German colony . The " Graf von Götzen " was the only German ship to survive . Lettow - Vorbeck then had its " Königsberg " gun removed and sent by rail to the main fighting front . The ship was scuttled after a floatplane bombing attack by the Belgians on Kigoma and before advancing Belgian colonial troops could capture it . It was later refloated and used by the British and is still in service today plying the lake under the Tanzanian flag . British Empire reinforcements , 1916 . General Horace Smith - Dorrien was assigned with orders to find and fight the " Schutztruppe " , but he contracted pneumonia during the voyage to South Africa which prevented him from taking command . In 1916 , General J . C . Smuts was given the task of defeating Lettow - Vorbeck . Smuts had a large army ( for the area ) , some 13 , 000 South Africans including Boers , British , and Rhodesians as well as 7 , 000 Indian and African troops . In addition , not under his direct command but fighting on the Allied side , was a Belgian force and a larger but ineffective group of Portuguese military units based in Mozambique . A large Carrier Corps of African porters under British command carried supplies for Smuts ' army into the interior . Despite all these troops from different allies , it was essentially a South African operation of the British Empire under Smuts ' control . During the previous year , Lettow - Vorbeck had also gained personnel and his army was now 1 , 800 Germans and some 12 , 000 Askaris . Smuts ' army attacked from several directions : the main attack was from the north out of British East Africa , while substantial forces from the Belgian Congo advanced from the west in two columns , over Lake Victoria on the British troop ship s and and into the Rift Valley . Another contingent advanced over Lake Nyasa ( Lake Malawi ) from the south - east . All these forces failed to capture Lettow - Vorbeck and they all suffered from disease along the march . One unit , 9th South African Infantry , started with 1 , 135 men in February , and by October its strength was reduced to 116 fit troops , without doing much fighting at all . However , the Germans nearly always retreated from the larger British troop concentrations and by September 1916 , the German Central Railway from the coast at Dar es Salaam to Ujiji was fully under British control . With Lettow - Vorbeck ' s forces now confined to the southern part of German East Africa , Smuts began to withdraw his South African , Rhodesian and Indian troops and replaced them with askaris of the King ' s African Rifles . By the start of 1917 , more than half the British Army in the theatre was composed of Africans , and by the end of the war , it was nearly all African troops . Smuts himself left the area in January 1917 to join the Imperial War Cabinet at London . Belgian - Congolese campaign . Belgian - Congolese participation in the campaign was sizeable — for the logistics alone some 260 , 000 carriers were mobilized , not counting troops . The colonial armed forces of the Belgian Congo , ' Force Publique ' , started their campaign on 18 April 1916 under the command of General Charles Tombeur , Colonel Molitor and Colonel Olsen . They captured Kigali on 6 May . The German askaris in Burundi fought well , but had to give way to the numerical superiority of " Force Publique " . By 6 June , Burundi as well as Rwanda was effectively occupied . " Force Publique " and the British Lake Force then started a thrust to capture Tabora , an administrative center of central German East Africa . They marched into German territory in three columns and took Biharamuro , Mwanza , Karema , Kigoma and Ujiji . After several days of heavy fighting , they secured Tabora . To forestall Belgian claims on the German colony , Smuts ordered their forces back to Congo , leaving them as occupiers only in Rwanda and Burundi . But the British were obliged to recall Belgian - Congolese troops to help for a second time in 1917 , and after this event the two allies coordinated campaign plans . Last years , 1917 – 1918 . Despite continued efforts to capture or destroy Lettow - Vorbeck ' s army , the British failed to end German resistance . First , Major General Reginald Hoskins ( of the KAR ) took over , then another South African , Major General J . L . van Deventer was assigned command . Van Deventer then launched a major offensive in July 1917 . The Germans ’ tactical skill could delay but it could not halt ; by early autumn they were pushed south . They were still able to tie down large British forces and even defeat them on occasion . In mid - October 1917 , Lettow - Vorbeck fought a pivotal and costly battle at Mahiwa , the " Schutztruppe " s last stand in defense of their colony , where they lost 519 men killed , wounded or missing and the British Nigerian brigade 2 , 700 killed , wounded or missing . After the news of the battle reached Germany , Lettow - Vorbeck was promoted to " Generalmajor " . In early November 1917 , the German High Command made an attempt to deliver much - needed supplies to Lettow - Vorbeck by air from Germany . The naval dirigible " L . 59 " traveled over in 95 hours , but in the end the mission failed when the airship received an " abort " message over the radio from the German admiralty . British units were closing in on the " Schutztruppe " and on 23 November 1917 , Lettow - Vorbeck crossed south into Portuguese Mozambique to gain supplies by capturing Portuguese garrisons . By leaving German East Africa , he no longer had to defer to the civil authority of Governor Schnee . With his caravans of troops , carriers , wives and children , he marched through Mozambique for the next nine months , avoiding capture , but unable to gain much strength . Lettow - Vorbeck ' s army was divided into three groups on the march . He eventually learned that he had lost a thousand - man detachment under " Hauptmann " Theodor Tafel , who was forced to surrender , being out of food and ammunition . The army then reentered German East Africa and crossed into Northern Rhodesia in August 1918 . On 13 November 1918 , two days after the Armistice was signed in France , the German Army took and occupied its last town , Kasama , which had been evacuated by the British . The next day at the Chambezi River , Lettow - Vorbeck was handed a telegram announcing the signing of the armistice and he agreed to a cease - fire : the ' Von Lettow - Vorbeck Memorial ' marks the spot in present - day Zambia . As requested , he marched his undefeated army to Abercorn and formally surrendered there on 23 November 1918 .