Although the location is sometimes identified with an ancient settlement mentioned by Yaqut and Al-Hamadani known as "Ghabra", the history of Diriyah proper dates back to the 15th century. According to the chroniclers of Nejd, the city was founded in 1446-7 by Mani Al-Mraydi, an ancestor of the Saudi royal family. Mani and his clan had come from the area of Al-Qatif in eastern Arabia, upon the invitation of Ibn Dir', who was then the ruler of a group of settlements that now make up Riyadh. Ibn Dir' is said to have been a relative of Mani' Al-Mraydi, and Mani's clan is believed to have left the area of Wadi Hanifa at some unknown date and were merely returning to their country of origin.
Initially, Mani' and his clan, known as the Mrudah, settled in Ghusaybah and Al-Mulaybeed. The entire settlement was named Al-Dir'iyah, after Mani's benefactor Ibn Dir'. Later on, the district of Turaif was settled. Many families from other towns or from the bedouin tribes of the nearby desert eventually settled in the area and by the 18th century Diriyah had become a well-known town in Nejd.
At that time, Muhammad ibn Saud emerged from a struggle within the ruling family of Al-Diriyah, the Al Migrin (sons of Migrin, a descendant of Mani'), and became the emir, or ruler, of Al-Diriyah. In 1744, Ibn Saud took in a fugitive religious scholar named Muhammad ibn Abd al-Wahhab, who hailed from the town of Al-Uyaynah, lying on the same wadi some 30 miles upstream. Ibn Saud agreed to implement Ibn Abdul Wahhab's religious views, and what later became known as the First Saudi State, with its capital at Diriyah, was born. Within the next several decades, Ibn Saud and his immediate descendants managed to subjugate all of Nejd, as well as the eastern and western regions of Arabia, and sent raids into Iraq. Diriyah quickly swelled in size and increased in wealth, becoming the largest town in Nejd and a major city in Arabia by the standards of the time. However, the Saudis'
