This is a list of wars that began between 1900 and 1944.
This period saw the outbreak of World War I (1914–1918) and World War II (1939–1945), which are among the deadliest conflicts in human history, with many of the world's great powers partaking in total war and some partaking in genocides. Depending on the source consulted, conflict deaths reached an all-time peak in either 1941 or 1942 at 2.96–7.71 million, during the height of the latter conflict.
Besides the aforementioned world wars, a number of smaller conflicts also took place. In Africa, conflicts of this era were mostly fought between European colonial forces on one side and native kingdoms and insurgents on the other. There are exceptions (e.g. the Italo-Turkish War, as well as intercolonial invasions of English, German, Italian and Vichy French possessions in the World Wars). Likewise, there were several large native rebellions in Southeast Asia against the European, Japanese and American colonial empires. The intercolonial Pacific War of World War II brought many countries into conflict in that theatre.
Other parts of Afro-Eurasia, as well as the Americas, saw a wide variety of conventional wars, civil wars, ethnic or political conflicts, revolutions, and small rebellions. Prior to 1940, Australia saw only sporadic conflict as the frontier wars entered its final stages. However, in World War II, Australia became the site of Axis naval activity and air raids.
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1900–1909 +1900–1909StartFinishName of ConflictBelligerentsVictorious party (if applicable)Defeated party (if applicable)190019051900–1905 phase of the Mat Salleh Rebellion North BorneoRebels19001920Dervish War Dervish State19001900War of the Golden Stool19001905Zande resistance Anglo-Egyptian SudanSultan Yam-bio's rebel forces19001902Muhammad Umar Khan's rebellion Forces loyal to Muhammad Umar Khan190019001900 Hamawand revoltHamawand rebels Supported by:
Sheikhs of Sulaymaniyah and Qaradāgh190019001900 Sudan revolt Anglo-Egyptian SudanSudanese rebels19001900French conquest of BornoBorno19001907Unrest in JavaPeasant rebels Lone-wolf robbers and arsonists190019031900–1903 uprising in southwest MadagascarRebels19001900Shoubak revolt of 1900Shoubakis19001900Sharjah conquest of Ras Al KhaimahEmirate of SharjahRas Al Khaimah19001900Russian invasion of Manchuria Yìhéquán19001901Mahsud Waziri blockade Mahsud rebels19001901Kuwaiti–Rashidi war Jabal Shammar Kuwait
House of Saud
Arab tribes
Al-Muntafiq Mutayr Otaibah Al-Dhafeer Ajman tribe Al-Hawajir Al Murrah Bani Khalid Subay' Suhool19011901Risings among the Agar Dinka Anglo-Egyptian SudanAgar Dinka rebels19011901Bastaard uprising of 1901 German South West AfricaBastaards from Grootfontein tribe19011907Subjugation of JambiJambi19011901French conquest of the Dendi KingdomDendi Kingdom19011903Liberating Revolution (Venezuela) Venezuela Liberal revolutionaries19011902Anglo-Aro War Aro Confederacy19011901Battle of Holy Apostles MonasteryArmenian fedayi190119031901 Mapondera RebellionForces loyal to Kadungure Mapondera19011936Holy Man's Rebellion SiamPhu Mi Bun Movement19021902Kala-i-Mor railway worker's revoltRebel railway workers19021902Haitian Civil War of 1902Anténor Firmin's rebels190219021902 Sudan revolt Anglo-Egyptian SudanSudanese rebels19021902Merauke uprisingMarind rebels19021904Kuanhama Rebellion of 1902-1904 Portuguese EmpireKuanhama19021904Bailundo revolt Portuguese EmpireOvimbundu Kingdoms Kisanji Luimbi19021904Ngiao Rebellion SiamShan rebels19021903Venezuelan crisis of 1902–1903 United States of Venezuela 19021902Kabul Khel expeditionKabul Khel rebels19021903Expeditions against the Bantin (Location: Kalimantan)Bantin19021906Korintji expeditions (Location: Sumatra)Korintji19021907Campaigns against Dayak (Location: Kalimantan)Dayak19021902Italian–Ottoman crisis of 190219031903Great Ming UprisingHeavenly Kingdom of the Great Mingshun190319031903 Tegale uprising Anglo-Egyptian SudanMuhammad al-Amin's rebel forces190319031903 uprising in Bukhara Anti-tax rebels19031910Risings among the Atwot Dinka Anglo-Egyptian SudanAtwot Dinka rebels19031905Rijal al-Ma rebellionRijal al-Ma19031903Kavango uprising German South West AfricaKavango rebels19031903Actions on YapenTribes of Yapen19031909Resistance in MinangkabauAnti-coffee rebels19031910Mentawei islands campaignAnti-Dutch forces19031916 (Solor)
1940
(Flores)Military actions in Flores and SolorAnti-Dutch forces19031903Kerinci ExpeditionAnti-Dutch forces19031903Battle of Jo-Laban Kuwait
Emirate of Nejd and Hasa
Arab tribes
Al-Muntafiq Ajman tribe Al Murrah Subay' Suhool Al-Hawajir Bani Khalid Al-Awazem Jabal Shammar
Mutayr19031903May Coup (Serbia)House of Obrenović19031903Ilinden–Preobrazhenie Uprising IMAROSMACKruševo RepublicStrandzha Republic19031904British expedition to TibetTibet19031904British conquest of the Sokoto Caliphate Sokoto Caliphate19031903British conquest of the Kano Emirate Kano Emirate19031907First Saudi–Rashidi War Part of the Unification of Saudi Arabia Emirate of Nejd and Hasa Emirate of Ha'il19031903Uprising of Namas in Maltahöhe German South West AfricaNama rebels19031904Bondelswarts uprising of 1904 German South West AfricaBondelswarts19041904Adam Wad Muhammad's uprising Anglo-Egyptian SudanAdam Wad Muhammad's rebel forces19041904Mahsud expedition of 1904Mahsud rebels190419041904 Ondonga uprising German South West AfricaOndonga rebels190419091904 Nama uprising German South West AfricaNama rebels190419041904 Sudan revolt Anglo-Egyptian SudanSudanese rebels19041904Campaign in the Gajo and Alas islandsPart of the Aceh WarAnti-Dutch forces19041904Dutch intervention in Bali (1904)Anti-Dutch forces19041904Resistance on TidoreTidore19041909Sulawesi expeditionsAnti-Dutch forces190419051904–1905 uprising in Madagascar Malagasy CatholicsRebels
Malagasy Protestants19041907Portuguese campaign against the Ovambo (See Battle of Mufilo) Portuguese Empire Ovambo19041904Vaccine RevoltAnti-vaccination rebels19041904Revolution of 1904 Uruguayan government National Party190419041904 Sasun uprisingArmenian fedayees19041908Herero WarsHerero and Nama peoples19041905Russo-Japanese War19041905Yemeni Rebellion of 1904 Part of the Yemeni–Ottoman ConflictsZaidis19041908Macedonian Struggle Hellenic Macedonian Committee Internal Macedonian Revolutionary Organization19051905Ping-liu-li UprisingRebels19051906Military actions in OninAnti-Dutch forces19051905Ottoman incursion into Persia Sublime State of Persia19051911Military actions Sumba and SumbawaAnti-Dutch forces19051911Persian Constitutional RevolutionSecret Center Social Democratic Party Society of Humanity Revolutionary Committee Secret Society
Semi-organized groups:
Ulama and seminary students Committee of Merchants Committee of Guild Elders Students of Dar ul-Funun, School of Political Science and School of Agriculture
Parliament Tabriz Council Society of Azerbaijanis Central Society Dashnak Society of Guilds Society of College Graduates Qajar Iran Nazmiyeh Cossack Brigade
Qajar Iran Cossack Brigade Russian EmpireJack A. Goldstone. The Encyclopedia of Political Revolutions Routledge, 29 apr. 2015 p 245 Shahsevans19051905Argentine Revolution of 1905Radical Civic Union19051905Shoubak Revolt of 1905Shoubakis19051905Łódź insurrectionPolish worker militias19051905Kurdish rebellion of 1905Kurdish rebels19051905Theriso revolt Supported By: Cretan rebels19051906Batang uprising Qing DynastyTibetan Buddhists19051907Russian Revolution of 1905 Revolutionaries19051907Maji Maji RebellionIndigenous rebels19051906Yemeni Expedition of 1905 Part of the Yemeni–Ottoman ConflictsZaidis19051905South Sulawesi expeditions of 1905South Sulawesi kingdoms of Bone, Luwu and Wajo19061906Taba Crisis of 190619061907Resistance in LombokMessianic rebels19061908Actions against fighters from Jambi in Indragiri (Location: Sumatra)Jambi19061906Ottoman invasion of Persia (1906) Sublime State of Persia19061906Sokoto Uprising of 1906Rebels190619061906 Mesopotamia uprisingMesopotamian tribesmen19061906Dutch intervention in Bali (1906)BadungTabananKlungkung19061906Bambatha RebellionZulu19071907Campaign against the MahafalyOnilahy (Mahafaly) kingdom19071918Asir rebellionIdrisid Emirate of Asir Supported by:
(1911–1912)
(1915–1918)19071907Dersim uprising of 1907 Part of the Kurdish rebels19071907War of 1907 Salvadoran exiles American filibusters Honduras19071907Huanggang Uprising Qing DynastyRebels19071907Huizhou Qinühu Uprising Qing DynastyRebels19071907Anqing Uprising Qing DynastyRebels19071907Qinzhou Uprising Qing DynastyRebels19071907Zhennanguan Uprising Qing DynastyRebels19071907Bitlis uprising (1907)Kurdish rebels19071910Dembos War of 1907-1910More info: Revoltas e Campanhas nos Dembos (1872–1919)
(In Portuguese) Portuguese EmpireDembos19071907Anti-Foreign RevoltForces loyal to Sheika Ma Al-Ainine (Ma al-'Aynayn ?)19071907Mutair revolt Emirate of Nejd and HasaMutair tribe190719071907 Romanian peasants' revolt Romanian peasants19071907Honduran-Nicaraguan War Honduras19071907Beipu uprisingHakka
Saisiyat190719071907 Diyarbakır uprising Ibrahim Pasha's autonomy in ViranşehirRebels of Diyarbakır19071908Zakka Khel raids on towns and villages in the British Raj British RajZakka Khel clan of the Afridi19081908Qin-lian Uprising Qing DynastyRebels19081908Hekou Uprising Qing DynastyRebels19081908Mapaoying Uprising Qing DynastyRebels19081909Bondelswarts rebellion of 1908 German South West AfricaBondelswarts19081908Wad Habuba RevoltNeo-Mahdist rebels19081909Lobi and Dyula revolt in MaliLobi and Dyula rebels19081914Mossi rebellions in Kouddigou and Fada N'gourmaMossi rebels19081908Annam uprising French IndochinaPeasant rebels19081908Mohmand Expedition of 1908 Part of the instability on the North-West Frontier British RajMohmand rebels19081908Bazar Valley campaign British RajZakka Khel clan of the Afridi19081908Kurdish uprising of 1908 Part of the Kurdish rebels19081908Buraida rebellion Emirate of Nejd and HasaForces loyal to Muhammad Aba al-Kehil19081908Battle of MarrakechForces of Mulay HafidForces of the Sultan of Morocco19081909Indigenous rebels19081908Young Turk RevolutionYoung Turks19081910/1914Hamawand rebellion Young Turks (Until 24 July 1908)
Ottoman Empire (From 24 July 1908)Kurdish rebels Hamawand tribe Ottoman Empire (Abdul Hamid II loyalists)(Until 24 July 1908)19081908Dutch intervention in Bali (1908)Karangasem Klungkung Gelgel19081910Actions in the Toba and Batak islandsAnti-Dutch forces19081915Actions in West-KalimantanAnti-Dutch forces19081908Dutch–Venezuelan crisis of 1908 Venezuela19081908Ngali WarNgali People190919091909 Battle of Al JawfRuwallah tribe Emirate of Ha'il19091909Nyasaland resistance NyasalandRebels19091909Battle of NiasAnti-Dutch forces19091911Actions on the Halmahera, Seram, Papua and Mentawei islandsAnti-Dutch forces19091909Kurdish uprising of 1909 Part of the Kurdish rebels19091909Estrada's rebellion Nicaraguan Conservative Party Nicaraguan Liberal Party (Government)19091909Kolašin Affair (1909)Black Hand19091910Zaraniq rebellion (1909–1910)Zaraniq tribesmen19091909Crazy Snake RebellionCreek19091910Second Melillan campaignRiffian people19091910Hauran Druze RebellionDruze rebels19091911Wadai WarWadai Sultanate
1910–1919 +1910–1919StartFinishName of ConflictBelligerentsVictorious party (if applicable)Defeated party (if applicable)19101910Al-Bejat RevolutionAl-Bejat clan19101910Gengxu New Army UprisingRebels191019101910 uprising in BukharaRebels19101910Portuguese conquest of the Angoche SultanateMozambiqueAngoche Sultanate19101910Uprising of Cape Nguni German South West AfricaNguni rebels19101912Xiong Mi Chang's rebellionRebels loyal to Xiong Mi Chang19101910Actions on Ajer HItam and near TimorAnti-Dutch forces19101911Actions in Langkat (Location: Sumatra)Anti-Dutch forces19101912Portuguese conquest of the Kasanje KingdomAngolaKasanje Kingdom19101910Monégasque RevolutionRebels19101910 Kuwait