This research examines the origins of the ruling family of the Saudi state. It shows that Al Saud come from the Bani Hanifa tribe, which belongs to the larger Bani Bakr bin Wa’il tribe, and follows their migration from Hijaz to the centre of the Arabian Peninsula, where they built a strong community before Islam. It also discusses the movement of some clans, including Al Murdah clan, led by the family’s ancestor Mani’ al-Muridi, who succeeded in founding a settlement along the Arabian Gulf coast before returning in the mid-9th century AH to their ancestral homeland in the Yamama region, where he founded Dir’iyah in 850 AH (1446). The study reviews the rulers of Dir’iyah from the descendants of Mani’ to Imam Mohammed bin Saud. It focuses on the historical and political events that accompanied the establishment of the Saudi state and discusses the common view among historians that the state was founded in 1157 AH (1744). This date is compared with Royal Decree No. A/371, which states that the correct founding date is mid-1139 AH (1727), supported by evidence. The research concludes by showing the efforts of Imam Mohammed bin Saud before and after the establishment of the state in strengthening its foundations, expanding its influence, and supporting its development.