Central Powers and their allies in 1914
Germany
System: Federal State, Constitutional Monarchy
Head of state: Emperor Wilhelm II
Area: 3,199,357 square kilometres (including colonies)
Population: 80,223,000
Military expenditures: 51.5 % of the total state expenditures in 1913
Military forces during peacetime: 806,800 men (excluding one-year volunteers)
Entry into the war: 1 August 1914 as a part of the Triple Alliance
Total mobilised by the end of the war: 11,000,000–13,250,000 men
Austria-Hungary
System: Constitutional monarchy
Head of state: Emperor of Austria and King of Hungary Franz Joseph I
Land: 676,060 square kilometres (including Bosnia and Herzegovina)
Population: 51,390,223
Military expenditures: 13.8 % of the total state expenditures in 1913
Military forces during peacetime: 414,679 men
Entry into the war: 28 July 1914 on the side of the Triple Alliance
Total mobilised by the end of the war: 7,800,000–9,000,000 men
Turkey
State system: Constitutional monarchy
Head of state: Sultan Mohamed V
Area: 2,799,850 km2
Population: 30,131,200
Military expenditure: 37.3 % of total state expenditure in 1912-1913
Peace establishment: ca 267,000 men
Entry to war: October 28, 1914, within Triple Alliance
Mobilized to end of war: 2,850,000–3,000,000 men
Bulgaria
State system: Constitutional monarchy
Head of state: King Ferdinand I
Area: ca 121,345 km2 (including conquests from Balkan wars 1912–1913)
Population: ca 9,337,513
Military expenditure: 21.5 % of total state expenditure in 1912-1913
Peace establishment: 62,257 men (1912, including navy)
Entry to war: September 14, 1915, within Triple Alliance
Mobilized to end of war: 1,200,000 men
Italy
State system: Constitutional monarchy
Head of state: King Victor Emanuel III
Area: 1,847,682 km2 (including colonies)
Population: ca 38,077,048
Military expenditure: N/A
Peace establishment: 264,121 men (budgeted size given for 1913-1914)
Entry to war: May 23, 1915, within Triple Entente
Mobilized to end of war: 5,000,000–5,615,000 men