From 1919 to 1948, the UK of Great Britain and Northern Ireland held control over Palestine, and Britain encouraged the Jews to migrate back to it. In 1948, 750,000 Jews lived in Palestine when the UN partitioned the area as the independent state of Israel. After this, 600,000 Palestinian Arabs fled out of Israeli territories to Jordan, Egypt, Syria, and beyond.
Through a series of wars, Israel expanded its area of territorial control and built settlements in Palestinian territories.