The region that is now Israel has a long and complex history, with various polities controlling the area throughout human history. The Land of Israel has hosted a wide variety of ethnic groups, including the Sea Peoples and the Israelites. The Jewish people formed their national and religious identity in the Land of Israel, with the Twelve Tribes of Israel forming the first constitutional monarchy in Palestine about 1000 B.C. . Jewish independence in Palestine lasted for 212 years. The Ottoman Empire conquered the region in 1517 and ruled it until the British conquered it in 1917. The British Mandate for Palestine officially started in 1924, and the first White Paper went into effect, capping Jewish immigration into Mandatory Palestine. The modern Zionist movement began in the late 19th century, with Jews immigrating to Palestine in large numbers. In 1948, the Jewish State of Israel was proclaimed in part of the ancient land of Israel.