Abdulaziz bin Abdul Rahman bin Faisal Al Saud (; 15 January 1876Ibn Saud's birth year has been a source of debate. It is generally accepted as 1876, although a few sources give it as 1880. According to British author Robert Lacey's book The Kingdom, a leading Saudi historian found records that show Ibn Saud in 1891 greeting an important tribal delegation. The historian reasoned that a 10 or 11-year-old child (as given by the 1880 birth date) would have been too young to be allowed to greet such a delegation, while an adolescent of 15 or 16 (as given by the 1876 date) would likely have been allowed. When Lacey interviewed one of Ibn Saud's sons prior to writing the book, the son recalled that his father often laughed at records showing his birth date to be 1880. Ibn Saud's response to such records was reportedly that "I swallowed four years of my life." p. 561 – 9 November 1953), known in the Western world as Ibn Saud (; Ibn Suʿūd),Ibn Saud, meaning "son of Saud" (see Arabic name), was a sort of title borne by previous heads of the House of Saud, similar to a Scottish clan chief's title of "the MacGregor" or "the MacDougal". When used without comment it refers solely to Abdulaziz bin Abdul Rahman, although prior to the capture of Riyadh in 1902 it referred to his father, Abdul Rahman bin Faisal . and known with his kunya Abu Turki (), was a Najdi war leader, statesman, and religious leader who became the founder and first King of Saudi Arabia, reigning from 23 September 1932 until his death in 1953. He had ruled parts of the kingdom since 1902, having previously been Emir, Sultan, King of Nejd, and King of Hejaz.

Ibn Saud was the son of Abdul Rahman bin Faisal, Emir of Nejd, and Sara bint Ahmed Al Sudairi. The family were exiled from their residence in the city of Riyadh in 1890. Ibn Saud reconquered Riyadh in 1902, starting three decades of conquests that made him the ruler of nearly all of central and north Arabia. He consolidated his control over Najd in 1921, then conquered the Hejaz in 1925. He extended his dominions into what later became the Kingdom of Saudi Arabia in 1932. Ibn Saud's victory and his support for Islamic revivalists would greatly bolster pan-Islamism across the Islamic world. Concording with Wahhabi beliefs, he ordered the demolition of several shrines, the Al-Baqi Cemetery and the Jannat al-Mu'alla. As King, he presided over the discovery of petroleum in Saudi Arabia in 1938 and the beginning of large-scale oil production after World War II. He fathered many children, including 45 sons, and all of the subsequent kings of Saudi Arabia as of .

Early life and family origins

The Al Saud family had been a power in central Arabia for the previous 130 years. Under the influence and inspiration of Wahhabism, the Saudis had previously attempted to control much of the Arabian Peninsula in the form of the Emirate of Diriyah, the first Saudi state, until its destruction by an Ottoman army in the Ottoman–Wahhabi war in the early nineteenth century.

Abdulaziz bin Abdul Rahman, also known as Ibn Saud, was born on 15 January 1876 in Riyadh. He was the fourth child and third son of Abdul Rahman bin Faisal, one of the last rulers of the Emirate of Nejd, the second Saudi state, a tribal sheikhdom centered on Riyadh. Ibn Saud's mother was Sara bint Ahmed Al Sudairi of the Sudairi family. She died in 1910. His full-siblings were Faisal, Noura, Bazza, Haya and Saad. He also had a number of half-siblings from his father's other marriages, including Muhammad, Abdullah, Ahmed, and Musaid, who all had roles in the Saudi government. Ibn Saud was taught Quran by Abdullah Al Kharji in Riyadh.

Exile and recapture of Riyadh In 1891, the House of Saud's long-term regional rivals led by Muhammad bin Abdullah Al Rashid conquered Riyadh. Ibn Saud was 15 at the time. He and his family initially took refuge with the Al Murrah, a Bedouin tribe in the southern desert of Arabia. Later, the Al Sauds moved to Qatar and stayed there for two months. Their next stop was Bahrain where they stayed briefly. The Ottoman State allowed them to settle in Kuwait where they settled and lived for nearly a decade. Ibn Saud developed a rapport with the Kuwaiti ruler Mubarak Al Sabah and frequently visited his majlis. His father, Abdul Rahman, did not endorse these visits, perceiving Mubarak's lifestyle as immoral and unorthodox.

On 14 November 1901 Ibn Saud and some relatives, including his half-brother Muhammad and several cousins (amongst them Abdullah bin Jiluwi), set out on a raiding expedition into the Nejd, targeting mainly tribes associated with the Rashidis. On 12 December they reached Al Ahsa and then proceeded south towards the Empty Quarter with the support from various tribes. Upon this Abdulaziz Al Rashid sent messages to Qatari ruler Jassim bin Mohammed Al Thani and to the Ottoman governor of Baghdad asking their help to stop Ibn Saud's raids on the tribes loyal to Al Rashid. These events led to a decrease in the number of Ibn Saud's raiders, and his father also asked him to cancel his plans to capture Riyadh. However, Ibn Saud did not cancel the raid and managed to reach Riyadh. On the night of 15 January 1902, he led 40 men over the city walls on tilted palm trees and took the city. The Rashidi governor of the city, Ajlan, was killed by Abdullah bin Jiluwi in front of his own fortress. The Saudi recapture of the city marked the beginning of the third Saudi State.Current Biography 1943, pp. 330–334

Following Ibn Saud's victory the Kuwaiti ruler Mubarak Al Sabah sent him an additional seventy warriors commanded by Ibn Saud's younger brother Saad. Upon settling in Riyadh, Ibn Saud took up residence in the palace of his grandfather, Faisal bin Turki.

Rise to power

Following the capture of Riyadh, many former supporters of the House of Saud rallied to Ibn Saud's call to arms. He was a charismatic leader and kept his men supplied with arms. Over the next two years, he and his forces recaptured almost half of the Nejd from the Rashidis.

In 1904, Abdulaziz bin Mutaib Al Rashid appealed to the Ottoman Empire for military protection and assistance. The Ottomans responded by sending troops into Arabia. On 15 June 1904, Ibn Saud's forces suffered a major defeat at the hands of the combined Ottoman and Rashidi forces. His forces regrouped and began to wage a guerrilla war against the Ottomans. Over the next two years, he was able to disrupt their supply routes, forcing them to retreat. Their efforts were rewarded in February 1905, when the Ottomans reversed their alliances and named Ibn Saud as qaimmaqam of southern Nejd, a title he held until the 1913 Anglo-Ottoman agreement. Ibn Saud's victory in Rawdat Muhanna, in which Abdulaziz Al Rashid died, ended the Ottoman presence in Nejd and Qassim by the end of October 1906. This victory also weakened Ibn Saud's alliance with the Kuwaiti ruler Mubarak Al Sabah, who began to fear Saudi preeminence in the region.

Ibn Saud completed his conquest of the Nejd and the eastern coast of Arabia in 1912. He then founded the Ikhwan, a military-religious brotherhood, which was to assist in his later conquests, with the approval of local Salafi ulema. In the same year, he instituted an agrarian policy to settle the nomadic pastoralist bedouins into colonies and to replace their tribal organizations with allegiance to the Ikhwan.

Ibn Saud offered his alliance to the British but was rebuffed, and in May 1914 he made a secret agreement with the Ottomans which would have made Ibn Saud the wali (governor) of Najd. With the outbreak of World War I, this agreement did not materialize, and the British government resumed diplomatic relations with him. The British agent, Captain William Shakespear, was well received by the Bedouin.Robert Wilson and Zahra Freeth. (1983). The Arab of the Desert. London: Allen & Unwin. pp. 312–13. Print. Britain sought similar diplomatic with other Arabian powers seeking to unify and stabilize the region. The Treaty of Darin in December 1915 made the lands of the House of Saud a British protectorate and attempted to define the boundaries of the developing Saudi state.John C. Wilkinson. (1993). Arabia's Frontiers: the Story of Britain's Boundary Drawing in the Desert. London u.a.: Tauris, pp. 133–39. Print In exchange, Ibn Saud pledged to again make war against Ibn Rashid, who was an ally of the Ottomans.

During this period, Ibn Saud also sought to strengthen his position through regional alliances. Sheikh Khaz'al Emir of Arabistan advised the Ottoman authorities that Ibn Saud was more valuable to them than Al-Ahsa and Qatif, urging them to support him as a strategic asset. As part of his diplomatic engagements, Ibn Saud traveled to Mohammerah as a guest of Sheikh Khaz'al. The two leaders arrived in Basra on the evening of November 26. The next morning, the British senior political officer, accompanied by two high-ranking British military representatives of the stationed army commander in Basra, boarded Sheikh Khaz’al's ship and presented Ibn Saud with the Sword of Honour along with a welcome letter from the army commander. He spent the day inspecting the British military base camps, their organization, and the latest military equipment, including warplanes, which he showed great interest in.Hakim Al-Mutairi, Al-Madina Al-Munawwara wa Al-Hisar Al-Akhir (The Last Siege of Medina), p. 567.

The British Foreign Office had previously begun to support Hussein bin Ali, Sharif of Mecca and Emir of the Hejaz, by sending T. E. Lawrence to him in 1915. The Saudi Ikhwan began to conflict with Hussein in 1917, just as his sons Abdullah and Faisal entered Damascus. The Treaty of Darin remained in effect until superseded by the Jeddah conference of 1927 and the Dammam conference of 1952, during both of which Ibn Saud extended his boundaries past the Anglo-Ottoman Blue Line. After Darin, he stockpiled the weapons and supplies which the British provided him, including a 'tribute' of £5,000 per month. After World War I Ibn Saud received further support from the British, including a glut of surplus munitions. He launched his campaign against the Al Rashidi in 1920; by 1922 they had been all but destroyed.

The defeat of the Al Rashidi doubled the size of Saudi territory because, after the war of Ha'il, Ibn Saud sent his army to occupy Al Jouf and the army led by Eqab bin Mohaya, the head of the Talhah branch of the Otaibah tribe. This allowed Ibn Saud the leverage to negotiate a new and more favorable treaty with the British in 1922, signed at Uqair. He met Percy Cox, British High Commissioner in Iraq, to draw boundaries and the treaty saw Britain recognize many of Ibn Saud's territorial gains. In exchange, Ibn Saud agreed to recognize British territories in the area, particularly along the Persian Gulf coast and in Iraq. The former of these were vital to the British, as merchant traffic between British India and the United Kingdom depended upon coaling stations on the approach to the Suez Canal.

In 1925, Ibn Saud's forces captured the holy city of Mecca from Sharif Hussein, ending 700 years of Hashemite rule. Following this he issued the first decree which was about the collection of zakat. On 8 January 1926, the leading figures in Mecca, Medina and Jeddah proclaimed Ibn Saud the King of Hejaz and the bayaa (oath of allegiance) ceremony was held in the Great Mosque of Mecca.

Ibn Saud raised Nejd to a kingdom as well on 29 January 1927.Joseph Kostiner. (1993). The Making of Saudi Arabia, 1916–1936: From Chieftaincy to Monarchical State Oxford University Press US, , p. 104 On 20 May 1927, the British government signed the Treaty of Jeddah, which abolished the Darin protection agreement and recognized the independence of the Hejaz and Nejd, with Ibn Saud as their ruler. For the next five years, Ibn Saud administered the two parts of his dual kingdom as separate units. He also succeeded his father, Abdul Rahman, as Imam.