Short-lived Arab kingdom proclaimed by Sharif Hussein bin Ali of Mecca during the Great Arab Revolt against the Ottomans, covering the western Arabian region of Hejaz.
Conquered by Ibn Saud's Emirate of Nejd in the Saudi-Hejazi War, formally ending 8 January 1926 (Wikidata dissolved date 1926) though military defeat came in 1925; later merged into the Kingdom of Saudi Arabia in 1932.
The modern scholarly history of Sharif Hussein's Hejaz kingdom and its fall to the Saudis, in print from NYU Press.