Read this: The populations of those lands did not accept Turkish rule. The Turks to them were foreigners with completely different customs, way of life, and language. Intervals when there was no unrest were rare. The Hungarians had thrown off Turkish rule by 1688. Serbia was created by the Serbian Revolution, 1815–1833. The Greek War of Independence, 1821–1832, created modern Greece, which recovered most of the lands of ancient Greece, but could not gain Constantinople. The Ottoman Porte was continuously under attack from some quarter in its empire, primarily the Balkans. Also, on a number of occasions in the early 19th century, American and British warships had to attack the Barbary pirates to stop their piracy and recover thousands of enslaved Europeans and Americans.

When was the Greek War of Independence?
What is the answer? (If it cannot be answered, return "unanswerable")
1821–1832