The Greek War of Independence, also known as the Greek Revolution or the Greek Revolution of 1821, was a successful war of independence by Greek revolutionaries against the Ottoman Empire between 1821 and 1829. In 1826, the Greeks were assisted by the British Empire, Kingdom of France, and the Russian Empire, while the Ottomans were aided by their North African vassals. The war led to the formation of modern Greece, which would be expanded to its modern size in later years. The revolution is celebrated by Greeks around the world as independence day on 25 March.

Filiki Eteria or Society of Friends was a secret political and revolutionary organization founded in 1814 in Odessa, whose purpose was to overthrow the Ottoman rule of Greece and establish an independent Greek State. Society members were mainly young Phanariot Greeks from Constantinople and the Russian Empire, local political and military leaders from the Greek mainland and islands, as well as several Orthodox Christian leaders from other nations that were under Hellenic influence, such as Karađorđe from Serbia, and Tudor Vladimirescu from Romania. One of its leaders was the prominent Phanariote Prince Alexander Ypsilantis. The Society initiated the Greek War of Independence in the spring of 1821.