At 830,000 sq. miles — slightly more than a fifth the size of the continental U.S., the Kingdom of Saudi Arabia is by far the largest country on the Arabian Peninsula. It was settled — sporadically, due to the harsh climate — starting in 3,000 BC by various nomadic tribes. A modern nation emerged with the rise to power of Muhammad bin Saud, who joined forces with an Islamic reformer, Muhammad Abd Al-Wahhab. The Saud family continued to rule, on and off, and consolidated its hold after the fall of the Ottoman Empire, uniting the disparate republics under one crown.

On this day, September 23, in 1932, King Abdul Aziz Al Saud united his conquered provinces of Al-Hasa in the east, Nejd in the center, and the Hijaz in west by the Red Sea.

Abdul Aziz presided over discovery of oil in his land and the distribution of oil extraction rights. The newfound wealth he spent in further putting down petty conflicts among the provinces, and establishing his own brand of Wahhabist ideology. Abdul Aziz fathered 45 sons during his lifetime, and five of them ruled the kingdom after him, including the current leader Abdullah bin Abdul-Aziz Al Saud, commonly known as King Abdullah.