Final answer:
Abdul Aziz Al-Sa'ud, known as Ibn Saud, captured Riyadh in 1902 and eventually established Saudi Arabia in 1932, becoming its first king after overthrowing Hussein Ibn Ali.
Step-by-step explanation:
The founder and first king of Saudi Arabia was Abdul Aziz Al-Sa'u00cdud, more commonly known as Ibn Saud. In 1902, Abdul Aziz Al-Sa'u00cdud began the unification of the Arabian Peninsula by capturing Riyadh. He was a skilled leader and tactician, who consolidated power through strategic marriages with other tribes, which was a common practice to establish alliances at the time. His efforts led to the formation of the modern Kingdom of Saudi Arabia in 1932, after he overthrew Hussein Ibn Ali, the king of Hejaz, in 1925.
The Arabian Peninsula, birthplace of Islam, recognized the holy cities of Mecca and Medina. The establishment of Saudi Arabia marked a significant transformation in the region's history, uniting various tribes under a single monarchy, the House of Saud. The contemporary boundaries and governance of the region are a direct legacy of Ibn Saud's actions and political engagements.