Nejd

Najd (نَجْدٌ, nad͡ʒd) is the geographic center of Saudi Arabia, accounting for about a third of the country's modern population and, since the Emirate of Diriyah, acting as the base for all unification campaigns by the House of Saud to bring Arabia under a single polity. Historic Najd was divided into three modern administrative regions still in use today. The Riyadh region, featuring Wadi Hanifa and the Tuwaiq escarpment, which houses easterly Yamama with the Saudi capital, Riyadh since 1824, and the Sudairi region, which has its capital in Majmaah. The second administrative unit, Al-Qassim, houses the fertile oases and date palm orchards spread out in the region's highlands along Wadi Rummah in central Najd with its capital in Buraidah, the second largest Najdi city, with the region historically contested by the House of Rashid to its north and the House of Saud to its east and south. The third administrative unit is northerly Ḥaʼil, which features the mountains of Jabal Shammar housing the Tayy capital of Ḥaʼil. The Najd region is home to Al-Magar, which was an advanced prehistoric culture of the Neolithic whose center lay in modern-day southwestern Najd. Al-Magar is possibly one of the first cultures in the world where widespread agriculture and the domestication of animals occurred, particularly that of the horse, during the Neolithic period, before climate changes in the region resulted in desertification. Radiocarbon dating of several objects discovered at Al-Magar indicate an age of about 9,000 years. In November 2017 hunting scenes showing images of what appears to be domesticated dogs resembling the Canaan dog and wearing leashes were discovered in Shuwaymis, an area about 370 km southwest of the city of Ha'il. Dated at 8,000 years before the present, these are thought of as the earliest known depictions of dogs in the world. In ancient times, Najd was settled by numerous tribes such as the Kindites, Tayy, and many others. Led by Usma bin Luai (عصمة بن لؤي), the Tayy sacked the mountains of Aja and Samra from Banu Tamim in northern Arabia in their exodus from Yemen circa CE 115.