The map above shows the rapidly shifting alliances during the 1910s in the Balkans. Over the course of the decade three different wars were fought there with very different alliances and outcomes.More about them below:First Balkan War (1912–1913)AlliancesBalkan League (against Ottoman Empire)SerbiaBulgariaGreeceMontenegroOpponentOttoman EmpireWhy this alliance formedShared goal: drive the Ottomans out of EuropeRise of nationalism in the BalkansWeakening of the Ottoman EmpireRussia encouraged cooperation (especially Serbia & Bulgaria)OutcomeWinners: Balkan LeagueOttomans lost almost all European territoryKey territorial gains:Serbia → gained Kosovo & parts of MacedoniaGreece → gained Thessaloniki & southern MacedoniaBulgaria → gained large parts of ThraceMontenegro → expanded slightlyBut a problem emerged:Disputes over Macedonia, especially between Serbia and BulgariaThis disagreement directly caused the next war.Second Balkan War (1913)AlliancesBulgaria (attacker)Fought alone initiallyAgainst Bulgaria:SerbiaGreeceLater joined by:RomaniaOttoman Empire (took advantage of Bulgaria’s weakness)Why alliances shiftedBulgaria felt it didn’t get its fair share of MacedoniaIt attacked Serbia and GreeceThis backfired, former allies united against BulgariaOthers joined opportunistically:Romania wanted landOttomans wanted territory backOutcomeWinner coalition:Serbia, Greece, Romania, Ottoman EmpireLoser:BulgariaKey results:Serbia → major expansion (became strongest Balkan state)Greece → secured southern Macedonia & ThessalonikiRomania → gained Southern DobrujaOttoman Empire → regained part of eastern Thrace (incl. Edirne)Bulgaria → lost territory and prestigeThis war reshaped alliances before WWI:Serbia grew stronger (worried Austria-Hungary)Bulgaria became resentful and isolatedBalkans in World War I (1914–1918)Major alliancesAllied Powers (Entente)SerbiaMontenegroLater joined by:Greece (1917)Romania (1916)Central PowersAustria-HungaryGermanyOttoman EmpireBulgaria (joined 1915)Why alliances shiftedSerbiaTarget of Austria-Hungary after assassination of Archduke Franz FerdinandSupported by Russia → joined AlliesBulgariaAngry after Second Balkan War lossesWanted Macedonia backJoined Central Powers (against Serbia)Ottoman EmpireSought protection and modernizationJoined Central Powers (aligned with Germany)RomaniaInitially neutralJoined Allies in 1916 to gain TransylvaniaGreeceDeep internal division:King favored GermanyGovernment favored AlliesEventually joined Allies in 1917Outcomes in the BalkansCentral Powers early successSerbia was defeated and occupied (1915)Bulgaria gained territory temporarilyTurning pointAllied forces regrouped (Salonika front)Bulgaria collapsed in 1918Final results (1918)Winners (Allies):Serbia → became core of new state:Kingdom of Serbs, Croats, and Slovenes (later Yugoslavia)Greece → gained territory in ThraceRomania → gained Transylvania and expanded greatlyLosers (Central Powers):Austria-Hungary → collapsed completelyOttoman Empire → lost most of its territoryBulgaria → lost territory again and was weakenedBig Picture: Why alliances kept shifting NationalismEach country wanted territory based on ethnic claims Macedonia problemMain source of conflict between Serbia, Bulgaria, and Greece OpportunismStates switched sides when it benefited them (e.g., Romania, Ottomans) Great Power influenceRussia backed SerbiaAustria-Hungary opposed SerbiaGermany supported Central PowersSimple SummaryFirst Balkan War → Balkan states unite to defeat OttomansSecond Balkan War → They fight each other over the spoilsWWI → Alliances split along larger global lines:Serbia vs Austria-HungaryBulgaria switches sides to get revengeMake sense?