The tribal areas that form the Assyrian homeland are parts of present-day northern Iraq (Nineveh Plains and Dohuk Governorate), southeastern Turkey (Hakkari and Tur Abdin), northwestern Iran (Urmia) and, more recently, northeastern Syria (Al-Hasakah Governorate). The majority have migrated to other regions of the world, including North America, the Levant, Australia, Europe, Russia and the Caucasus during the past century. Emigration was triggered by events such as the massacres of Diyarbakır, the Assyrian genocide (concurrent with the Armenian and Greek genocides) during World War I by the Ottoman Empire and allied Kurdish tribes, the Simele massacre in Iraq in 1933, the Iranian Revolution of 1979, Arab Nationalist Ba'athist policies in Iraq and Syria, the rise of Islamic State of Iraq and the Levant (ISIL) and its takeover of most of the Nineveh Plains.