Described by the Admiralty as the most powerful tribe in Central Arabia and second among all the nomads only to the Anizah, the Otaibah held the eastern side of the Hejaz with the volcanic harrahs between the pilgrim road and the central Arabian steppes, grazing east to Qasim and Washm. Great camel-breeders divided into the Ruqah of the Hejaz and the Berqah of the eastern desert, they were courted alternately by the Sharif of Mecca and by Ibn Saud, and were at feud with the Harb and the Qahtan.
Not an ending: the Otaibah passed between Sharifian and Saudi allegiance through the 1910s, furnished some of the most militant Ikhwan settlements, and were absorbed into the Kingdom of Saudi Arabia proclaimed in 1932. The tribe continues in Najd and the Hejaz today.
Its section 'The Ateibah' is the fullest published account of this confederation's dirah, divisions (Ruqah/Berqah), pasture quality and its shifting allegiance between the Sharif and Ibn Saud. Full text read on the Internet Archive.
The standard scholarly study of exactly the process that ends this record — how the Najdi tribal confederations, the Otaibah prominent among them, were converted into Ikhwan settlements and then subordinated to a monarchical state. Existence verified on Open Library (/works/OL2632215W, ISBN 9780195074406).