The 1948 Arab-Israeli War began after the United Nations proposed a plan to partition Palestine into separate Jewish and Arab states. Following the declaration of the state of Israel on May 14, 1948, neighboring Arab countries, including Egypt, Jordan, Syria, Lebanon, and Iraq, invaded in support of the Palestinian Arabs. The conflict lasted until March 1949, resulting in significant territorial changes. Israel gained more land than initially proposed by the UN plan, while many Palestinians became refugees. The war established the foundation for ongoing tensions and conflicts in the region.