Participants in World war I - wikipedia Participants in World war I This article does not cite any sources. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. ( May 2017 ) Allies ( at one point or another ) Central Powers Neutral countries This is a list of countries that participated in World War I, sorted by alphabetical order. Contents 1 Allies 2 The Central Powers 3 Neutral countries 4 Declarations of war 5 See also 6 Notes and references Allies The `` Entente Powers '' are also known as the Allies of World War I or the Allies Arab Rebels Andorra Belgium Brazil China Costa Rica Cuba Czechoslovak Emirate of Nejd and Hasa France Greece Guatemala Haiti Honduras Italy ( Italian Empire ) Japan Liberia Montenegro Nepal New Hebrides Nicaragua Panama Portugal Romania Russia Russian Republic Russian SFSR Serbia Thailand United Kingdom Canada India Australia New Zealand Malta South Africa Rhodesia Sri Lanka British crown colonies United States Alaska Guam Hawaii Northern Mariana Islands Philippine Islands Puerto Rico United States Virgin Islands Other Non Independent ethnic groups : Armenians, Assyrians, Poles, Pontic Greeks The Central Powers Austria - Hungary Bulgaria Dervish State German Empire German colonial empire Jabal Shammar Ottoman Empire * Senussi Sultanate of Darfur Belarusian People 's Republic Kingdom of Lithuania ( 1918 ) Kingdom of Poland ( 1917 - 1918 ) United Baltic Duchy Ukrainian State Neutral countries Afghanistan -- received a German diplomatic mission trying to convince it to act against the British in India Argentina Bolivia Bhutan Chile Colombia Denmark Ecuador El Salvador Ethiopia -- Supported Central Powers and was on the verge of entering the war before Iyasu V 's dethronement Iran -- Civil dispute and Allied Campaign against Ottomans Liechtenstein -- Had a customs and monetary union with Austria - Hungary Luxembourg -- Never declared war on the Central Powers despite being invaded and occupied by Germany Bogd Khaanate of Mongolia / Mexico -- Declined an alliance with Germany ( see Zimmermann Telegram ) Monaco The Netherlands ( Dutch Empire ) Traded with both sides. Norway -- Gave naval assistance to the United Kingdom. Paraguay Peru San Marino - 20 volunteers joined on the Italian ( Allied ) side. Cut diplomatic ties with Austria -- Hungary, but it never entered the war Spain ( Spanish Territories in Africa ) Spitsbergen -- Danish - Norwegian co-dominium Sweden -- Non-belligerent Switzerland -- Switzerland did declare a `` state of siege '' Uruguay Venezuela Declarations of war European military alliances prior to the war. Allies and Central Powers, early August 1914. Allies and Central Powers, mid 1918. The following table shows the timeline of the several declarations of war among the belligerent powers. Entries on a yellow background show severed diplomatic relations only, not actual declarations of war. Date Declarer On 1914 July 28 Austria - Hungary Serbia August 1 Germany Russia August 3 Germany France August 4 Germany Belgium United Kingdom Germany August 5 Montenegro Austria - Hungary August 6 Austria - Hungary Russia Serbia Germany August 9 Montenegro Germany August 11 France Austria - Hungary August 12 United Kingdom Austria - Hungary August 22 Austria - Hungary Belgium August 23 Japan Germany August 25 Japan Austria - Hungary November 1 Russia Ottoman Empire November 2 Serbia Ottoman Empire November 3 Montenegro Ottoman Empire November 5 United Kingdom France Ottoman Empire 1915 May 23 Italy Austria - Hungary August 21 Italy Ottoman Empire October 14 Bulgaria Serbia October 15 United Kingdom Montenegro Bulgaria October 16 France Bulgaria October 19 Italy Russia Bulgaria 1916 March 9 Germany Portugal March 15 Austria - Hungary Portugal August 27 Romania Austria - Hungary Italy Germany August 28 Germany Romania August 30 Ottoman Empire Romania November 1 Bulgaria Romania 1917 April 6 United States Germany April 7 Cuba Panama Germany April 10 Bulgaria United States April 13 Bolivia Germany April 20 Ottoman Empire United States July 2 Greece Germany Austria - Hungary Ottoman Empire Bulgaria July 22 Siam Germany Austria - Hungary Ottoman Empire August 4 Liberia Germany August 14 China Germany Austria - Hungary October 6 Peru Germany October 7 Uruguay Germany October 26 Brazil Germany December 7 United States Austria - Hungary December 7 Ecuador Germany December 10 Panama Austria - Hungary December 16 Cuba Austria - Hungary 1918 April 23 Guatemala Germany May 8 Nicaragua Germany Austria - Hungary May 23 Costa Rica Germany July 12 Haiti Germany July 19 Honduras Germany November 10 Romania Germany See also World War I portal Allies of World War I Triple Entente Triple Alliance Central Powers Participants in World War II Casualties of World War I Notes and references ^ British Empire was the common term for the United Kingdom and its overseas possessions at this time. The term refers to the colonies it controlled, to the Indian Empire, which, while not officially designated a colony, was functionally indistinguishable from one, and the British Dominions - former colonies which were self - governing in most respects but whose foreign policy was controlled by London ; Australia, Canada, Newfoundland, New Zealand and South Africa. At that time, the United Kingdom of Great Britain and Ireland also included the entire island of Ireland. World War I Home fronts Theatres European Balkans Western Front Eastern Front Italian Front Middle Eastern Gallipoli Sinai and Palestine Caucasus Persia Mesopotamia South Arabia African South West East Kamerun Togoland North Asian and Pacific Tsingtao German New Guinea and Samoa At sea North Atlantic U-boat campaign Mediterranean North Sea Baltic Indian, Pacific and South Atlantic Oceans Papeete Madras Penang Cocos Coronel Falkland Islands Más a Tierra Principal participants ( people ) Entente powers Belgium Brazil China France French Empire Greece Italy Japan Montenegro Portuguese Empire Romania Russia Russian Empire Russian Republic Serbia United Kingdom British Empire United States Central Powers Germany Austria - Hungary Ottoman Empire Bulgaria Timeline Pre-War conflicts Scramble for Africa ( 1880 -- 1914 ) Russo - Japanese War ( 1905 ) First Moroccan ( Tangier ) Crisis ( 1905 -- 06 ) Agadir Crisis ( 1911 ) Italo - Turkish War ( 1911 -- 12 ) French conquest of Morocco ( 1911 -- 12 ) First Balkan War ( 1912 -- 13 ) Second Balkan War ( 1913 ) Prelude Origins Sarajevo assassination Anti-Serb riots in Sarajevo July Crisis Autumn 1914 Battle of the Frontiers Battle of Cer First Battle of the Marne Siege of Tsingtao Battle of Tannenberg Battle of Galicia Battle of the Masurian Lakes Battle of Kolubara Battle of Sarikamish Race to the Sea First Battle of Ypres 1915 Second Battle of the Masurian Lakes Second Battle of Ypres Battle of Gallipoli Second Battle of Artois Battles of the Isonzo Gorlice -- Tarnów Offensive Great Retreat Second Battle of Champagne Kosovo Offensive Siege of Kut Battle of Loos 1916 Erzurum Offensive Battle of Verdun Lake Naroch Offensive Battle of Asiago Battle of Jutland Battle of the Somme first day Brusilov Offensive Baranovichi Offensive Battle of Romani Monastir Offensive Battle of Transylvania 1917 Capture of Baghdad First Battle of Gaza Zimmermann Telegram Second Battle of Arras Second Battle of the Aisne Kerensky Offensive Third Battle of Ypres ( Passchendaele ) Battle of Mărășești Battle of Caporetto Southern Palestine Offensive Battle of Cambrai Armistice of Erzincan 1918 Operation Faustschlag Treaty of Brest - Litovsk Spring Offensive Battle of Goychay Battle of Aghsu Battle of Kyurdamir Second Battle of the Marne Battle of Baku Hundred Days Offensive Vardar Offensive Battle of Megiddo Third Transjordan attack Meuse - Argonne Offensive Battle of Vittorio Veneto Battle of Aleppo Armistice of Salonica Armistice of Mudros Armistice of Villa Giusti Armistice with Germany Other conflicts Mexican Revolution ( 1910 -- 20 ) Somaliland Campaign ( 1910 -- 20 ) Libyan resistance movement ( 1911 -- 43 ) Maritz Rebellion ( 1914 -- 15 ) Zaian War ( 1914 -- 21 ) Indo - German Conspiracy ( 1914 -- 19 ) Senussi Campaign ( 1915 -- 16 ) Volta - Bani War ( 1915 -- 17 ) Easter Rising ( 1916 ) Anglo - Egyptian Darfur Expedition ( 1916 ) Kaocen Revolt ( 1916 -- 17 ) Central Asian Revolt ( 1916 - 17 ) Russian Revolution ( 1917 ) Finnish Civil War ( 1918 ) Post-War conflicts Russian Civil War ( 1917 -- 21 ) Ukrainian -- Soviet War ( 1917 -- 21 ) Armenian -- Azerbaijani War ( 1918 -- 20 ) Georgian -- Armenian War ( 1918 ) German Revolution ( 1918 -- 19 ) Revolutions and interventions in Hungary ( 1918 -- 20 ) Hungarian -- Romanian War ( 1918 -- 19 ) Greater Poland Uprising ( 1918 -- 19 ) Estonian War of Independence ( 1918 -- 20 ) Latvian War of Independence ( 1918 -- 20 ) Lithuanian Wars of Independence ( 1918 -- 20 ) Third Anglo - Afghan War ( 1919 ) Egyptian Revolution ( 1919 ) Polish -- Ukrainian War ( 1918 -- 19 ) Polish -- Soviet War ( 1919 -- 21 ) Irish War of Independence ( 1919 -- 21 ) Turkish War of Independence Greco - Turkish War ( 1919 -- 22 ) Turkish -- Armenian War ( 1920 ) Iraqi revolt ( 1920 ) Polish -- Lithuanian War ( 1920 ) Vlora War ( 1920 ) Franco - Syrian War ( 1920 ) Soviet -- Georgian War ( 1921 ) Irish Civil War ( 1922 -- 23 ) Aspects Opposition Pacifism Anti-war movement Deployment Schlieffen Plan ( German ) Plan XVII ( French ) Warfare Military engagements Naval warfare Convoy system Air warfare Cryptography Room 40 Horse use Poison gas Railways Strategic bombing Technology Trench warfare Total war Christmas truce Last surviving veterans Civilian impact Atrocities Prisoners Casualties Economic history 1918 flu pandemic Destruction of Kalisz Rape of Belgium German occupation of Belgium German occupation of Luxembourg German occupation of northeastern France Ober Ost Ottoman people Armenian Genocide Assyrian genocide Pontic Greek genocide Urkun ( Kyrgyzstan ) Blockade of Germany Women Australia Popular culture German prisoners of war in the United States Agreements Partition of the Ottoman Empire Sykes -- Picot Agreement Agreement of Saint - Jean - de-Maurienne French - Armenian Agreement Damascus Protocol Paris Peace Conference Venizelos -- Tittoni agreement Treaties Treaty of Brest - Litovsk Treaty of Lausanne Treaty of London Treaty of Neuilly Treaty of St. Germain Treaty of Sèvres Treaty of Trianon Treaty of Versailles Consequences Aftermath `` Fourteen Points '' League of Nations World War I memorials Centenary outbreak Portal World War I portal Retrieved from `` https://en.wikipedia.org/w/index.php?title=Participants_in_World_War_I&oldid=848697468 '' Categories : World War I by country Hidden categories : Articles lacking sources from May 2017 All articles lacking sources Talk Contents About Wikipedia Беларуская Deutsch Français Հայերեն Bahasa Indonesia 日本 語 Português Română Русский Српски / srpski Türkçe Українська 中文 5 more Edit links This page was last edited on 3 July 2018, at 17 : 48 ( UTC ). Text is available under the Creative Commons Attribution - ShareAlike License ; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy. Wikipedia ® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization. About Wikipedia

Question: who were the first two countries involved in world war 1
Answer: Austria-Hungary