Portuguese campaign in Mozambique
Part ofEast African campaign (World War I)
15th Infantry Battalion departs fromLisbon for African colonies, 1914
Date 24 August 1914 – November 1918 Location Portuguese East Africa Result Portuguese victory
Belligerents
German Empire German East Africa	First Portuguese Republic Portuguese East Africa British Empire
Commanders and leaders
Wolfgang Weck Paul von Lettow-Vorbeck Erich Müller	Pedro Massano de Amorim Eduardo Costa † Major da Silveira João Teixeira Pinto † Eric Gore-Browne †
Strength
Unknown	August 1914: 1,477[1] October 1916: 2,700[2]

ThePortuguese campaign in Mozambique duringWorld War I was part of the broaderEast African Campaign. This lasted until the collapse of German forces inEast Africa in November 1918.

At the outbreak ofWorld War I, the proximity ofPortuguese Mozambique toGerman East Africa, along with the old alliance between Portugal and Britain, placed Mozambique in a risky position. Despite Portugal maintaining a policy of neutrality, it was under pressure from Britain, its ally, to support the British military in Africa. This included allowing British forces to pass through Portuguese territory and improving their defenses along Mozambique's northern border.^[1]

By early August 1914, tensions were rising along Mozambique's borders, particularly in the south, where aBoer revolt was imminent. To suppress this uprising, Britain requested not only rifles but also permission to move British troops through Mozambique. Portugal deemed it essential to reinforce the frontier, especially the area along theRovuma River, which had a very limited Portuguese military presence. On August 18, 1914, Portugal dispatched its first expedition to Mozambique, consisting of approximately 1,477 men, most from the 3rd Battalion of the15th Infantry Regiment. The mission was to establish military posts along theRovuma River.^[3]

The frontier posts established along theRovuma River were very basic. The post at Maziua, situated far from the main Portuguese stronghold ofPorto Amélia, was one of the weakest, defended by a small garrison of just one sergeant and half a dozen indigenous soldiers from the Niassa Company's police force. On August 24, 1914, the German forces launched an unexpected and unjustified attack on the post. The German forces raided and massacred the indigenous soldiers who were guarding the post, and the sergeant Eduardo Costa was killed during the attack.^[4][5]

TheKionga Triangle had long been disputed between Portugal and Germany. When Portugal entered World War I in March 1916, reclaiming the Kionga Triangle became a priority for local forces. At the time, the Portuguese garrison included around 1,500 Europeans and 2,800 African troops, many weakened by illness. Without waiting for reinforcements, Major da Silveira launched an offensive early in April, assembling a force of 400 at Palmas, near the Kionga. The small German detachment made no attempt to resist, and by 10 April the Portuguese had occupied the Triangle.^[6]

However, German forces on the opposite bank continued to launch raids. Major da Silveira organized a river crossing with naval support from the cruiser Adamastor and gunboat Chaimite to counter the Germans. On 27 May, native troops attempted to land at Mwambo, but German defenders waited until the boats were in close range before opening fire, forcing the Portuguese to abandon their attempts.^[7]

On 25 November, 1917, at 07:00, the Portuguese garrison atNgomano was warned of an impending attack but was unprepared. The Germans distracted them with artillery fire while crossing theRovuma River upstream. The Germans flanked the camp with six infantrycompanies from multiple directions.^[8] The Portuguese were surprised by the attack from the rear, and their defenses collapsed after their officers were killed, despite preparing for the initial attack. With the Portuguese lacking weapons and facing heavy casualties, they eventually surrendered, even though they had enough supplies to continue fighting.^[9]

On July 1, 1918, the Germans entered Namacurra, three battalions supported by twoBritish King's African Rifle companies underColonel Gore-Browne, facing three German companies led by Captain Müller. By July 3, von Lettow had deployed his main force, pushing the Portuguese back to the Namacurra River. During their retreat, 100 men drowned, including Gore-Browne. The fighting ended in the afternoon of July 3.^{[10][11][12][13]}

• Matias, Diogo (2010)."As operações militares de manutenção do Império Português em África: Uma visão sobre as tácticas usadas na perspectiva da doutrina actual"(PDF).
• Paice, Edward (2008) [2007].Tip & Run: The Untold Tragedy of the Great War in Africa. London: Phoenix.ISBN 978-0-7538-2349-1.
• Downes, Walter (1919).With the Nigerians in German East Africa. London: Methuen & Co.OCLC 10329057.
• David Smith, Graham Turner (2022).The East Africa Campaign 1914–18: Von Lettow-Vorbeck’s Masterpiece, Bloomsbury Publishing. ISBN 9781472848925
• Gaudi, Robert (2017).African Kaiser: General Paul Von Lettow-Vorbeck and the Great War in Africa, Hurst. ISBN 9781849048675
• Erez Manela, Robert Gerwarth (2014). Empires at War: 1911–1923, OUP Oxford. ISBN 9780191006944
• David F. Burg, L. Edward Purcell (2010).Almanac of World War I, University Press of Kentucky. ISBN 9780813127453
• Stacke, Henry Fitz Maurice (1941).Military Operations East Africa. Vol. 1.

• East African campaign (World War I)
• African theatre of World War I
• East Africa
• Military history of German East Africa
• Military history of Mozambique
• Battles of World War I involving Germany
• Battles of World War I involving the United Kingdom
• Battles of World War I involving Portugal
• 1910s in Africa
• 1910s in Mozambique
• Military campaigns involving Germany