The Arabian Peninsula has supported human settlement for at least 85,000 years based on stone tool discoveries at Al-Fayah in the Nafud Desert. During pluvial periods when the peninsula received substantially more rainfall than today, hunter-gatherers occupied territories that are now extreme desert. Rock art in the Hail region depicts cattle herding and predates 7,000 BCE, documenting a time when grasslands covered areas that became the Rub' al Khali and Nafud Desert. These carvings show domesticated animals, human figures, and hunting scenes across sandstone outcrops near Jubbah and Shuwaymis, indicating stable populations with livestock economies. The transition from humid conditions to aridity forced concentration of settlement near permanent water sources and along trade corridors connecting the Mediterranean world with the Indian Ocean.
Incense trade routes crossed western Arabia from at least 1,000 BCE, linking frankincense and myrrh production zones in Yemen with markets in Egypt, the Levant, and Mesopotamia. Caravan cities developed at intervals determined by camel range, typically 25 to 30 kilometers apart for daily stages. Al-Ula emerged as a major station where the Nabataeans carved elaborate tombs into sandstone cliffs at Hegra between the first century BCE and first century CE. More than 110 monumental tombs survive at Hegra, the largest Nabataean site outside Petra in Jordan. Inscriptions at these tombs record the names of deceased individuals, their tribal affiliations, and construction dates according to the Nabataean calendar. The Nabataean occupation ended around 106 CE when Rome annexed their territory, but trade routes continued functioning under different control structures. Dumat al-Jandal in the north served as another key oasis town with fortifications and wells documented in Assyrian records from the eighth century BCE.
The Hijaz region along the Red Sea coast held strategic value because of ports providing access to African and Asian trade networks. Jeddah functioned as a harbor serving Mecca from at least the seventh century CE, though the exact founding date remains undocumented. Mecca itself developed around the Zamzam well as a pre-Islamic religious center where various Arab tribes conducted pilgrimages to the Kaaba, a cubic stone structure that existed before Islam. The city sat at the convergence of trade routes running north-south along the Red Sea coast and east-west connections to the interior. Medina, known in the pre-Islamic period as Yathrib, was an agricultural oasis with date palm cultivation and a mixed population including Arab tribes and Jewish clans who had migrated from the Levant centuries earlier.
Muhammad ibn Abdullah was born in Mecca around 570 CE into the Quraysh tribe, which controlled the city and its pilgrimage economy. At age 40, in 610 CE, he reported receiving revelations in the Cave of Hira on Jabal al-Nour mountain outside Mecca. These revelations, which Muslims believe came from God through the angel Gabriel, continued over 23 years and were compiled into the Quran after his death. Opposition from Meccan leaders who saw monotheism as threatening their polytheistic pilgrimage trade forced Muhammad and his followers to migrate to Medina in 622 CE. This migration, the Hijra, marks year one in the Islamic calendar. In Medina, Muhammad established a political and religious community that combined immigrant Muslims from Mecca with converts from local tribes. Military conflicts with Mecca occurred at Badr in 624 CE, Uhud in 625 CE, and during a siege of Medina in 627 CE. In 630 CE, Muhammad returned to Mecca with a force that secured the city without major bloodshed. He destroyed the idols in the Kaaba while preserving the structure itself, establishing it as the direction of prayer for Muslims. Muhammad died in Medina in 632 CE and was buried in the house of his wife Aisha, which now lies within Al-Masjid an-Nabawi.
After Muhammad's death, leadership passed to a succession of caliphs who expanded Islamic rule far beyond Arabia. The first four caliphs governed from Medina until 661 CE, when the Umayyad dynasty moved the capital to Damascus. The Abbasid dynasty that followed in 750 CE relocated the capital to Baghdad. Arabia became a peripheral region in these empires despite containing Islam's holiest sites. The Hijaz fell under the control of the Mamluks based in Egypt from 1250 CE until the Ottoman Empire conquered the region in 1517 CE. The Ottomans administered the Hijaz primarily to oversee the annual Hajj pilgrimage, which brought revenue and religious legitimacy. They appointed governors in Mecca and Medina and maintained a garrison in Jeddah but exercised limited control over the interior regions of Najd and the Empty Quarter.
Central Arabia in the Najd region remained politically fragmented into tribal territories and small towns. Diriyah, established on the banks of Wadi Hanifa northwest of present-day Riyadh, became the seat of the Al Saud family by the mid-15th century. In 1744 CE, Muhammad ibn Saud, the ruler of Diriyah, formed an alliance with Muhammad ibn Abd al-Wahhab, a religious reformer advocating a return to what he considered the original practices of Islam. Ibn Abd al-Wahhab rejected popular practices such as venerating saints, visiting tombs, and celebrating the Prophet's birthday as innovations contrary to monotheism. This alliance combined political power with religious authority, creating what outsiders called the Wahhabi movement though adherents prefer the term Salafism or refer simply to their practice as Islam. The first Saudi state expanded from Diriyah across much of the Arabian Peninsula between 1744 and 1818 CE, capturing Mecca in 1803 and Medina in 1804. This expansion alarmed the Ottoman Empire, which commissioned Muhammad Ali Pasha of Egypt to destroy the Saudi state. Egyptian forces razed Diriyah in 1818 and took the Saudi ruler Abdullah ibn Saud to Istanbul for execution.
The second Saudi state established its capital at Riyadh in 1824 under Turki ibn Abdullah, who reconsolidated control over Najd. This state lasted until 1891 when internal conflicts allowed the rival Al Rashid family based in Hail to capture Riyadh. The Al Saud family went into exile in Kuwait. Abdulaziz ibn Abdul Rahman Al Saud, born around 1875, led a force of approximately 60 men from Kuwait and captured Riyadh in January 1902 by scaling the walls of Masmak Fortress at night. This raid began a 30-year military campaign to unify territories across the peninsula. Abdulaziz conquered the Al-Ahsa region along the Persian Gulf coast in 1913, removed Ottoman control from the Asir Mountains in the southwest during World War I, and captured Hail in 1921. In 1924 his forces took the Hijaz from the Hashemite Sharif of Mecca, securing control of Mecca and Medina. On September 23, 1932, Abdulaziz declared the unification of his territories as the Kingdom of Saudi Arabia with himself as king.
The discovery of oil transformed Saudi Arabia from one of the world's poorest countries to one of its wealthiest within a generation. American geologist Karl Twitchell surveyed the kingdom in the 1930s and recommended exploring for oil. Standard Oil of California acquired concession rights in 1933. The first commercial oil well, Dammam No. 7, struck oil in March 1938 at a depth of 1,440 meters after earlier wells had failed. The California Arabian Standard Oil Company, later renamed the Arabian American Oil Company or Aramco, developed the oil fields in the Eastern Province. Oil exports began in 1939 but remained limited until after World War II. Production increased rapidly in the 1950s and 1960s, reaching one million barrels per day in 1960 and 3.5 million barrels per day by 1970. Revenue from oil allowed the government to build infrastructure, establish free education and healthcare systems, and subsidize essential goods.