The Concert of Europe was a general agreement among the great powers of 19th-century Europe to maintain the European balance of power, political boundaries, and spheres of influence. Never a perfect unity and subject to disputes and jockeying for position and influence, the Concert was an extended period of relative peace and stability in Europe following the Wars of the French Revolution and the Napoleonic Wars which had consumed the continent since the 1790s. There is considerable scholarly dispute over the exact nature and duration of the Concert. Some scholars argue that it fell apart nearly as soon as it began in the 1820s when the great powers disagreed over the handling of liberal revolts in Italy, while others argue that it lasted until the outbreak of World War I and others for points in between. For those arguing for a longer duration, there is generally agreement that the period after the Revolutions of 1848 and the Crimean War (1853–1856) represented a different phase with different dynamics than the earlier period.
Prince Metternich, Austrian chancellor and foreign minister, as well as an influential leader in the Concert of Europe
A great power is a sovereign state that is recognized as having the ability and expertise to exert its influence on a global scale. Great powers characteristically possess military and economic strength, as well as diplomatic and soft power influence, which may cause middle or small powers to consider the great powers' opinions before taking actions of their own. International relations theorists have posited that great power status can be characterized into power capabilities, spatial aspects, and status dimensions.
Great powers are recognized in several international structures, including the United Nations Security Council.
In the mid-19th century, German historian Leopold von Ranke attempted to scientifically document the great powers.
The "Big Four" at the Paris Peace Conference of 1919: David Lloyd George, Vittorio Emanuele Orlando, Georges Clemenceau, and Woodrow Wilson
The "Big Three" of Europe at the Yalta Conference: Winston Churchill, Franklin D. Roosevelt, and Joseph Stalin