Greek nationalism (or Hellenic nationalism) refers to the nationalism of Greeks and Greek culture. Greek nationalism, as an ideology, originated and evolved in pre-modern times. It became a major political movement beginning in the 18th century, which culminated in the Greek War of Independence (1821–1829) against the Ottoman Empire. It became a potent movement in Greece shortly prior to, and during World War I under the leadership of nationalist figure Eleutherios Venizelos who pursued the Megali Idea and managed to liberate Greece in the Balkan Wars and after World War I, briefly annexed the region of Izmir before it was retaken by Turkey. Today Greek nationalism remains important on the Greco-Turkish dispute over Cyprus.