King Abdullah I of Jordan

Abdullah, with British support, established the Emirate of Transjordan, becoming its Emir. This created a buffer state between British Palestine and the Arabian Peninsula, laying the foundation for the modern Hashemite Kingdom of Jordan.

The Emirate of Transjordan gained full independence from the British Mandate, and Abdullah was crowned King of the Hashemite Kingdom of Jordan. The treaty with Britain was revised, granting Jordan sovereignty over its foreign and domestic affairs.

Following the 1948 Arab-Israeli War, Abdullah annexed the West Bank, including East Jerusalem, into Jordan. This move was condemned by most Arab states and the Arab League, but it significantly expanded Jordan's territory and population.

King Abdullah was assassinated by a Palestinian gunman while entering the Al-Aqsa Mosque in Jerusalem. The assassin was motivated by Abdullah's perceived willingness to negotiate with Israel and his annexation of the West Bank. His son Talal succeeded him.