The beginning
Imam Muhammad bin Saud was born in 1090 AH, 1679. In the middle of 1139 AH, February 1727, he began his rule in Diriyah at a time when the town was weak and divided and plague was spreading, and founded the first Saudi state.
What he built
He united the two halves of Diriyah under one rule, organised the economic affairs of the state and built the wall of Diriyah to defend it. Later he united most of Najd and secured the routes of pilgrimage and trade.
He died in 1179 AH, 1765, and was succeeded by his son, Imam Abdulaziz. The day his rule began is commemorated every year on Founding Day, 22 February.