Holy Alliance
In 1821, the Greeks revolted against centuries-long Ottoman rule. They won numerous victories early on and declared independence on 1 January 1822. However, the declaration contradicted the principles of the Congress of Vienna and of the Holy Alliance, which imposed a European equilibrium of the "status quo", outlawing any possible change. In contrast to what happened elsewhere in Europe, the Holy Alliance did not intervene to stop the liberal Greek insurgents.