Balkan League
The signing of a secret bilateral defensive alliance between Serbia and Bulgaria. Serbia and Bulgaria sign treaties to split between them the land of Vardarrr Macedonia
Permanent historical records · Updated 2026-11-03
1912 in Bulgaria
Explore 37 historical events and records for Bulgaria in 1912.
Historical records for Bulgaria in 1912
Sorted by month and day. Records with no month are shown last. Showing 37 of 37 unique records.
37Unique records
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31Named events on this page
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8Places on this page
March
Serbo-Bulgarian Alliance
Approves the secret alliance with Serbia.
Serbo-Bulgarian Alliance
Signs the alliance establishing Serbian-Bulgarian cooperation against the Ottoman Empire.
May
Balkan League
Expanded by a military contract
Serbo-Bulgarian Military Convention
Negotiates operational cooperation between the Bulgarian and Serbian armies.
Balkan League
This agreement is later followed by a similar one between Bulgaria and Montenegro, thus forming a network of alliances in the Balkans, aimed at Turkey.
Greco-Bulgarian Treaty
Greece, not wishing to be left out of a possible alliance against the Ottoman Empire and the corresponding partition of territory, begins negotiations with Bulgaria on a defensive alliance resulting in the Greco-Bulgarian Treaty
Greco-Bulgarian Treaty
Concludes a defensive treaty with Greece.
October
Balkan League
The first state to declare war is Montenegro, starting the First Balkan War. After issuing an ultimatum to the Porte on October 13, Bulgaria declares war on Turkey on October 17
Declaration of War
After issuing an ultimatum to the Porte on October 13, Bulgaria declares war on Turkey on October 17
First Army Advance
Commands Bulgaria's First Army in Thrace.
Thrace Offensive
Leads Bulgarian armies into Eastern Thrace.
Siege of Adrianople
Begins operations against Adrianople.
Battle of Lule Burgas
Helps win a major First Balkan War battle.
Balkan League
The First Balkan War breaks out following an impossible ultimatum given to the Porte
November
Chatalja Line
Bulgarian forces fail to break the Chatalja line.
December
Battle of Elli
Following a ceasefire in December between the Ottoman Empire and Bulgaria, Serbia and Montenegro, the Turkish fleet twice exited the Dardanelles but was twice defeated in the battles of Elli and Lemnos
Battle of Lemnos
Following a ceasefire in December between the Ottoman Empire and Bulgaria, Serbia and Montenegro, the Turkish fleet twice exited the Dardanelles but was twice defeated in the battles of Elli and Lemnos
Ceasefire
Following a ceasefire in December between the Ottoman Empire and Bulgaria, Serbia and Montenegro, the Turkish fleet twice exited the Dardanelles but was twice defeated in the battles of Elli and Lemnos
Other events (month unknown)
Adrianople Remains Under Siege
Bulgarian forces maintain the siege through difficult winter conditions while broader Balkan negotiations continue.
Adrianople Siege Begins
Bulgarian forces invest Adrianople and begin the siege that will dominate operations in eastern Thrace.
Balkan League Presses Ottoman Demands
Tsar Ferdinand joins other Balkan rulers in escalating demands for reforms in Ottoman European territories before the First Balkan War.
Battle of Kirk Kilisse
Radko Dimitriev leads Bulgarian Third Army forces in the operations that help rout Ottoman positions near Kirk Kilisse.
Bulgarian Advance Reaches Chataldja
Bulgarian forces approach the fortified Chataldja line outside Constantinople after victories farther west.
Bulgarian Armies Cross Frontier
Bulgarian troops advance into Ottoman Thrace during the opening campaign of the First Balkan War.
Bulgarian Command Plans Thracian Advance
Mihail Savov helps direct Bulgarian military preparations for the main offensive across the Ottoman frontier.
Bulgarian Mobilization Orders Issued
Ferdinand orders the mobilization that prepares Bulgaria for a campaign against Ottoman forces in Thrace.
Bulgarian Offensive Targets Eastern Thrace
Ferdinand supports the strategic thrust toward Adrianople and Constantinople while Serbian and Greek allies operate elsewhere.
Invasion of Ottoman Territory
Bulgaria attacks Eastern Thrace, stopped at the outskirts of Constantinople in the Chatalja line
Invasion of Thrace
Takes three Bulgarian Armies into Thrace in the direction of Adrianople
Lule Burgas Fighting Intensifies
Dimitriev commands Bulgarian troops in the prolonged and bloody Lule Burgas campaign in Thrace.
Ottoman Retreat Follows Kirk Kilisse
Dimitriev pursues the advantage after Bulgarian victories compel Ottoman troops to withdraw toward the southeast.
Partition
An alliance is agreed between Bulgaria and Serbia to partition Macedonia
Second Army Encircles Adrianople
Nikola Ivanov commands Bulgarian Second Army during the investment of the Ottoman fortress of Adrianople.
Siege Batteries Pressure Adrianople
Ivanov's forces use increasingly concentrated artillery to wear down Ottoman fortifications around the city.
Thracian Supply Lines Become Critical
Savov and Bulgarian commanders must sustain armies and artillery over extended routes through contested Thrace.
War With Ottoman Empire Begins
Bulgaria enters the First Balkan War as its armies prepare to advance into Ottoman Thrace.
How these records were prepared
Generated from the World History Database historical_events table. Identical display records are collapsed; descriptions otherwise retain the stored text. Coverage and source quality vary. Check primary and specialist sources before citing individual historical claims.