The Balkan Wars Double Greek Territory
Serbia, Greece, Bulgaria, and Montenegro gang up on a weakened Ottoman Empire, then Greece and Serbia turn on Bulgaria
Quick facts
- First Balkan War declared
- 17 October 1912
- First Balkan War ends
- 30 May 1913
- Second Balkan War
- June-August 1913 (Bulgaria vs. former allies)
- Greek prime minister
- Eleftherios Venizelos
What happened
On 17 October 1912, Serbia and Greece declared war on the Ottoman Empire, joining Montenegro and Bulgaria in an alliance encouraged by Russia to seize the empire's remaining European territory while the Ottomans were simultaneously fighting Italy over Libya. The combined Balkan forces routed the Ottoman army and drove Turkish forces from almost all of their European holdings within weeks. A peace treaty ending the First Balkan War was signed 30 May 1913 after months of negotiation among the European powers in London, partitioning Macedonia among the victors. Dissatisfied with its share, Bulgaria attacked its former allies Serbia and Greece in June 1913, starting the Second Balkan War; Bulgaria was defeated, and Serbia and Greece ended up with most of Macedonia. Under Prime Minister Eleftherios Venizelos, Greek territory roughly doubled, adding Thessaloniki, southern Epirus, most of Macedonia, and Crete.
Why it matters
The Balkan Wars turned Greece from a small kingdom confined to the Peloponnese, central Greece, and the Cyclades into a substantially larger state with major cities like Thessaloniki under its control, and they cemented Venizelos as the dominant figure in Greek politics for the next two decades. The territorial appetite the wars satisfied also fed directly into the Megali Idea, the vision of an even larger Greece incorporating Constantinople and Greek communities across Asia Minor, that would drive Greek foreign policy into catastrophe less than a decade later.
How we know
The Balkan Wars are documented in the diplomatic record of the London peace conference and the Treaty of Bucharest, and Venizelos's leadership during the conflict is described in the official biographical materials of the Greek foundation established in his name.
Sources
- History.com (A&E Television Networks). Serbia and Greece declare war on Ottoman Empire in First Balkan War · Reputable sourcehistory.com · The domain "history.com" is on our Reputable source registry. · Link is live and its text matches the event's key terms (Jul 2026)
- National Research Foundation "Eleftherios K. Venizelos". Biography · General sourcevenizelos-foundation.gr · Cited as a "reference" source (no stronger domain match). · Link is live and its text matches the event's key terms (Jul 2026)
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