There are different theories about where the ancestors of the Arabian originally lived. Most evidence suggests the proto-Arabian came from the area along the northern edge of the Fertile Crescent.[74] Another hypothesis suggests the southwestern corner of the Arabian peninsula, in modern-day Yemen, where three now-dry riverbeds indicate good natural pastures existed long ago, perhaps as far back as the Ice Age.[75][76] This hypothesis has gained renewed attention following a 2010 discovery of artifacts dated between 6590 and 7250 BCE in Al-Magar, in southwestern Saudi Arabia, that appeared to portray horses.[77]
The proto-Arabian horse may have been domesticated by the people of the Arabian peninsula known today as the Bedouin, some time after they learned to use the camel, approximately 4,000–5,000 years ago.[76][78] One theory is that this development occurred in the Nejd plateau in central Arabia.[71] Other scholars, noting that horses were common in the Fertile Crescent but rare in the Arabian peninsula prior to the rise of Islam, theorize that the breed as it is known today only developed in large numbers when the conversion of the Persians to Islam in the 7th century brought knowledge of horse breeding and horsemanship to the Bedouin.[79] The oldest depictions in the Arabian Peninsula of horses that are clearly domesticated date no earlier than 1800-2000 BCE.[77]
Regardless of origin, climate and culture ultimately created the Arabian. The desert environment required a domesticated horse to cooperate with humans to survive; humans were the only providers of food and water in certain areas, and even hardy Arabian horses needed far more water than camels in order to survive (most horses can only live about 72 hours without water). Where there was no pasture or water, the Bedouin fed their horses dates and camel's milk.[80] The desert horse needed the ability to thrive on very little food, and to have anatomical traits to compensate for life in a dry climate with wide temperature extremes from day to night. Weak individuals were weeded out of the breeding pool, and the animals that remained were also honed by centuries of human warfare.[81]
The Bedouin way of life depended on camels and horses: Arabians were bred to be war horses with speed, endurance, soundness, and intelligence.[81][82] Because many raids required stealth, mares were preferred over stallions as they were quieter, and therefore would not give away the position of the fighters.[81] A good disposition was also critical; prized war mares were often brought inside family tents to prevent theft and for protection from weather and predators.[83] Though appearance was not necessarily a survival factor, the Bedouin bred for refinement and beauty in their horses as well as for more practical features.[82]