Page 8 – Republic of Portugal


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1916 Map

Map of the Republic of Portugal

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General facts

  • Population: 6.2 million (1916)
  • Capital: Lisbon (1911 population 435,000)


  • Head of State:
    • President Bernardino Marchado (6 August 1915 – 5 December 1917)
    • President Sidónio Pais (28 April – 14 December 1918)
    • President João do Canto e Castro (14 December 1918 – 5 October 1919)
    • President António José de Almeida (5 October 1919 – 5 October 1923)
  • Head of Government:
    • Prime Minister Afonso Costa (29 November 1915 – 16 March 1916)
    • Prime Minister António José de Almeida (16 March 1916 – 25 April 1917)
    • Prime Minister Afonso Costa (25 April – 8 December 1917)
    • Prime Minister Sidónio Pais (8 December 1917 – 23 December 1918)
    • Prime Minister João Tamagnini Barbosa (23 December 1918 – 27 January 1919)
    • Prime Minister José Relvas (27 January – 30 March 1919)
    • Prime Minister Domingos Pereira (30 March – 30 June 1919)

Participation in the War

  • Entered the war: 9 March 1916 (Germany declared war on Portugal)
  • Ceased hostilities: 11 November 1918 (armistice with Germany)
  • Ended belligerent status: 10 August 1920 (Treaty of Sèvres signed with Ottoman Empire)

Military Force


  • Peacetime strength 1916: 30,000
  • Total mobilised 1916: 75,000
  • Total mobilised during war: 140,000

Portuguese Expeditionary Corps, Western Front 1916–1918

On 23 June 1916 the Portuguese government announced that it would raise an expeditionary force of 30,000 men to serve alongside the other Allied armies in France. The first units of the Corpo Expedicionário Português (Portuguese Expeditionary Corps) disembarked at Brest on 2 February 1917 and saw combat for the first time on 17 June. The Portuguese troops held a sector of the front between Laventie and La Bassée in Flanders and relied on the British Army for logistical and high-level operational support. Ongoing political upheaval at home undermined the ability of the Portuguese Expeditionary Corps to take part in Allied offensive operations. It was often deliberately starved of reinforcements for months at a time.

A total of 54,000 men served in the Portuguese Expeditionary Corps on the Western Front between February 1916 and November 1918.

Portuguese Colonial Army in Africa, 1914–1918

In 1914 Portugal still possessed a large overseas empire, most of it in Africa. The two main African Portuguese territories were Angola, on the west coast of southern Africa, with German South West Africa (modern-day Namibia) to its south, and Portuguese East Africa (modern-day Mozambique), on the east coast with the Union of South Africa to its south and German East Africa to its north.

Both Angola and Portuguese East Africa had Portuguese Colonial Army garrisons of around 1500 men, African troops led by European officers. With the outbreak of the war in 1914 Portugal sent reinforcements to both colonies, nervous that the fighting in the neighbouring German African colonies would spill over the rudimentary borders into its territories.

After Germany declared war on Portugal in March 1916 the Portuguese government sent more reinforcements to Mozambique (the South Africans had captured German South West Africa in 1915). These troops supported British, South African and Belgian military operations against German colonial forces in German East Africa.

In December 1917, German colonial forces led by Colonel Paul von Lettow-Vorbeck invaded Mozambique from German East Africa. Portuguese, British and Belgian forces spent all of 1918 chasing Lettow-Vorbeck and his men across Mozambique, German East Africa and Northern Rhodesia.

Portugal sent a total of 40,000 reinforcements to Angola and Mozambique during the war.


  • Peacetime strength 1916: 4000

Fleet (1916)

  • Battleships (pre-Dreadnoughts): 1
  • Light cruisers: 4
  • Destroyers: 3
  • Submarines: 1



Portuguese Expeditionary Corps (Western Front)
Dead (all causes): 1689
Wounded: 13,751

Portuguese Colonial Army (Portuguese Africa)
Dead: 802 (Angola), 4723 (Mozambique)


  • Peter Abbott, Armies in East Africa 1914–18, Osprey, Oxford, 2002
  • Hernani Cidade, ‘Portugal at War’, in Purnell’s History of the First World War, Volume 3, Purnell, London, 1969–1971, pp. 1274–5
  • Spencer C. Tucker (ed.), The Encyclopedia of World War I: Volume 3, ABC-CLIO, Santa Barbara CA, 2005
How to cite this page

'Republic of Portugal', URL:, (Ministry for Culture and Heritage), updated 28-Aug-2014