Abdul Aziz bin Abdul Rahman ibn Faisal Al Saud, also known by several abbreviated forms of this name, or simply as Ibn Saud, was first monarch of Saudi Arabia. He was born into the House of Saud (also Sa'ud), which had historically maintained dominion over an area of what was then known as Arabia called Nejd.
He was born in Riyadh. In 1890, at the age of ten, Saud followed his family into exile in Kuwait following the conquering of the family's lands by the Rashidi. He spent the remainder of his childhood in Kuwait as a "penniless exile." 
In 1901, at the age of 21, Ibn Saud succeeded his father, Abdul Rahman bin Faisal, to become the leader of the Saud dynasty with the title Sultan of Nejd. It was at this time that he set out to reconquer his family lands from Ibn Rashid in what is now called Saudi Arabia. In 1902, together with a party of relatives and servants, he recaptured Riyadh with only twenty men by assassinating the Rashidi governor of the city. Ibn Saud was considered a "magnetic" leader, and many former supporters of the House of Saud once again rallied to its call following the capture of Riyadh.
For two years following his dramatic capture of Riyadh, Ibn Saud recaptured almost half of Nejd from the Rashidi. In 1904, however, Ibn Rashid appealed to the Ottoman Empire for assistance in defeating the House of Saud. The Ottomans sent troops to Arabia, setting Ibn Saud on the defensive. The armies of the House of Saud suffered a major defeat on June 15, 1904, but his forces soon reconstituted and resumed the offensive as the Turkish troops left the country due to supply problems.
Ibn Saud finally consolidated control over the Nejd in 1912 with the help of an organized and well-trained army. During World War I, the British government attempted to cultivate favor with Ibn Saud, but generally favored his rival Sherif Hussein ibn Ali, leader of Hejaz, whom the Sauds were almost constantly at war with. Despite this, the British entered into a treaty in December of 1915 making the lands of the House of Saud a British protectorate. In exchange, Ibn Saud pledged to again make war against Ibn Rashid, who was an ally of the Ottomans.
Ibn Saud did not, however, immediately make war against Ibn Rashid, despite a steady supply of weapons and cash (£5,000 Sterling per month) supplied by the British. He argued with the British that the payment he received was insufficient to adequately wage war against an enemy as powerful as Ibn Rashid. In 1920, however, the House of Saud finally marched again against the Rashidi, extinguishing their dominion in 1922. The defeat of the Rashidis doubled the territory of the House of Saud, and British subsidies continued until 1924.
In 1925 the Sauds defeated Husayn in battle.
In 1927, following the defeat of Husayn, the British government recognized the power of the Saud family, led by Ibn Saud, over much of what is today Saudi Arabia. At this time he changed his own title from Sultan of Nejd to King of Hejaz and Nejd.
From 1927 to 1932, Ibn Saud continued to consolidate power throughout the Arabian Peninsula. In 1932, having conquered most of the Peninsula, Saud renamed the area from the lands of Nejd and Hejaz to Saudi Arabia. He then proclaimed himself King of Saudi Arabia, with the support of the British government.
Oil and the rule of Ibn Saud
Oil was discovered in Saudi Arabia in 1938, and Ibn Saud responded by granting substantial authority over Saudi oil fields to American oil companies. In the early days of the oil boom most oil revenues received by the government of Saudi Arabia were immediately directed to the coffers of the royal family. As the income from oil grew, however, Ibn Saud began to spend some revenues on improving the lives of his subjects.
Saud forced many nomadic tribes to settle down and abandon "petty wars" and vendettas. He also began to fight crime in Saudi Arabia, particularly crime against pilgrims visiting the holy cities of Mecca and Medina.
Ibn Saud positioned Saudi Arabia as neutral in World War II, but was generally considered to favor the Allies.
In 1948, Saud participated in the Arab-Israeli war. The contribution of Saudi Arabia was generally considered token.
Ibn Saud died in Taif.
Ibn Saud had 52 children (of which 37 were boys), by several different women. They are:
- By Wadhba bint Muhammad al-Hazzam
- Turki (1900-1919)
- Saud (January 12, 1902 - February 23, 1969)
- By Bazza
- Nasser (born 1919)
- Bandar (born 1923)
- Fawwaz (born 1934)
- By Princess Jauhara bint Musaid Al Saud
- Muhammad (1910-1988)
- Khaled (1913 - June 13, 1982)
- Anud (born 1917)
- By Jauhara bint Saad al-Sudairy
- Saad (1920 - 1990s)
- Musaid (born 1923)
- Abdalmohsen (1925-1985)
- By Shahida
- Mansur (1922 - May 2, 1951)
- Mishal (born 1926)
- Qumasha (born 1927)
- Muteb (born 1931)
- By Princess Haya bint Sa'ad al-Sudairy (1913 - April 18, 2003)
- Badr (born 1933)
- Abdalillah (born 1935)
- Abdalmajid (born 1940)
- By Hessa bint Ahmad al-Sudairy (these are known as the "Sudairi Seven")
- Fahd (born 1923)
- Sultan (born January 5, 1928)
- Abdalrahman (born 1931)
- Turki (born 1932)
- Nayef (born 1934)
- Salman (born 1936)
- Ahmad (born 1940)
- By unknown
- Khaled (born 1903)
- Faisal (April 1904 - March 25, 1975)
- Fahd (1905-1919)
- Abdallah (born August 1921)
- Shaikha (born 1922)
- Talal (1930-1931)
- Talal (born 1931)
- Badr (1931-1932)
- Mishari (1932 - May 23, 2000)
- Nawwaf (born 1933)
- Thamir (1937 - June 27, 1959)
- Majed (October 19, 1938 - April 12, 2003)
- Mamduh (born 1940)
- Sattam (born January 21, 1941)
- Hathloul (born 1941)
- Nura (died 1930)
- Abdalsalam (1941)
- Mashhur (born 1942)
- Jiluwi (1942-1944)
- Muqren (born September 15, 1945)
- Hamud (born 1947)
- Sara (c. 1916 - June 2000).
All of these carry the surname "bin Abdul Aziz Al Saud" for men and "bint Abdul Aziz Al Saud" for women. Ibn Saud is the father of all the Kings of Saudi Arabia that have succeeded him. King Saud succeeded his father as regent of Saudi Arabia in 1953, three months after being appointed Prime Minister by his father. In 1964 King Saud was deposed by the Saudi Council of Ministers and succeeded by King Faisal, another of Ibn Saud's sons. Faisal was followed by two other sons, Khalid and Fahd. According to the Saudi Basic Law of 1992, the King of Saudi Arabia must be a son or grandson of Ibn Saud