From 1912 Abdulaziz Ibn Saud encouraged and then organised the settlement of nomadic tribes in hijar, agricultural colonies built around wells and a mosque, where Wahhabi missionaries taught a strict doctrine and where the settlers, the Ikhwan, could be mobilised as a standing force. The first and largest was al-Artawiyah; over the following fifteen years between 120 and 200 such settlements were founded. Sedentarisation broke the tribes' seasonal migration and their autonomy, and the Ikhwan became the shock troops of Saudi expansion, taking Hail in 1921 and the Hijaz in 1924-25, where the sack of Taif in September 1924 killed several hundred civilians and prompted flight from Mecca. When Ibn Saud restrained raiding across the new borders with Iraq and Transjordan, the Ikhwan revolted and were defeated at Sabilla in March 1929, after which their leaders were imprisoned and their settlements disarmed. The hijar system nonetheless established the pattern of settled bedouin communities that persisted in the Saudi state.
Abdulaziz Ibn Saud's state settled bedouin tribes in religious agricultural colonies and used them to conquer central and western Arabia
No defensible denominator exists. Central Arabia was never enumerated before the Saudi census of 1974, and estimates of the nomadic population of Najd in the 1910s and 1920s are guesses drawn from British political reports; the number of hijar settlements (roughly 200 by the late 1920s) and their estimated 50,000-60,000 residents is better attested than the bedouin population from which they were drawn.
The settlement programme itself was not lethal. Deaths came in the campaigns it enabled: several hundred civilians at Taif in 1924 by most accounts, and around a thousand at Sabilla in 1929, both figures from British reporting and later histories rather than records.
British political agents' reports and later histories of the Saudi conquest document the killings at Taif in 1924.
Saudi Arabia