Ibn Saud was born on 15 January 1875 in Riyadh in the region of Najd in central Arabia. He was the son of Abdul Rahman bin Faisal, last ruler of the Emirate of Nejd, the "Second Saudi State", a tribal sheikhdom centered on Riyadh. His family, the House of Saud, had been a power in central Arabia for the previous 130 years. Under the influence and inspiration of Wahhabi Islam, 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. Ibn Saud's mother was a member of the Sudairi family, Sarah Al Sudairi. She died in 1910.
In 1890, the House of Saud's long-term regional rivals, the Rashidis, 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. Their final destination was Kuwait, where they lived for nearly a decade.
In the spring of 1901, Ibn Saud and some relatives, including a half-brother, Mohammad, and several cousins, set out on a raiding expedition into the Najd, targeting for the most part tribes associated with the Rashidis. As the raid proved profitable, it attracted more participants. The raiders' numbers peaked at over 200, but numbers dwindled over the ensuing months.
In the autumn, the group made camp in the Yabrin oasis. While observing Ramadan, he decided to attack Riyadh and retake it from the Al Rashid. On the night of 15 January 1902, he led 40 men over the walls of the city on tilted palm trees and took the city. The Rashidi governor of the city, Ajlan, was killed in front of his own fortress. The Saudi recapture of the city marked the beginning of the Third Saudi State.
In 1904, Abdulaziz of Al Rashid (a.k.a. Ibn 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 guerrilla warfare against the Ottomans. Over the next two years, he was able to disrupt their supply routes, forcing them to retreat. The victory of Ibn Saud in Rawdat Muhanna, in which Abdulaziz died, ended the Ottoman presence in Najd and Qassim by the end of October 1906.
He completed his conquest of the Najd 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.
The British Foreign Office had previously begun to support Sharif Hussein bin Ali, Emir of the Hejaz by sending T. E. Lawrence (a.k.a. Lawrence of Arabia) to him in 1915. The Saudi Ikhwan began to conflict with Hussein, Sharif of Mecca also 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, he 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 Talhah tribe. This allowed Ibn Saud the leverage to negotiate a new and more favorable treaty with the British. Their treaty, signed at Uqair in 1922, where he met Percy Cox, British High Commissioner in Iraq, to draw boundaries saw Britain recognize many of his 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.
His newfound oil wealth brought with it a great deal of power and influence that Ibn Saud would use to advantage in the Hijaz. He forced many nomadic tribes to settle down and abandon "petty wars" and vendettas. He also began widespread enforcement of the new kingdom's ideology, based on the teachings of Muhammad Ibn Abd al-Wahhab. This included an end to traditionally sanctioned rites of pilgrimage, recognized by the orthodox schools of jurisprudence, but at odds with those sanctioned by Muhammad ibn Abd al-Wahhab. In 1926, after a caravan of Egyptians on the way to Mecca were beaten by his forces for playing bugles, he was impelled to issue a conciliatory statement to the Egyptian government. In fact, several such statements were issued to Muslim governments around the world as a result of beatings suffered by the pilgrims visiting the holy cities of Mecca and Medina. With the uprising and subsequent decimation thereafter of the Ikhwan in 1929 via British air power, the 1930s marked a turning point. With his rivals eliminated, Ibn Saud's ideology was in full force, ending nearly 1400 years of accepted religious practices surrounding the Hajj, the majority of which were sanctioned by a millennium of scholarship.
Ibn Saud established a Shura Council of the Hijaz as early as 1927. This Council was later expanded to 20 members, and was chaired by the king's son, Faisal.
With international recognition and support, Ibn Saud continued to consolidate his power. By 1928, his forces had overrun most of the central Arabian Peninsula. However, the alliance between the Ikhwan and the Al Saud collapsed when Ibn Saud forbade further raiding. The few portions of central Arabia not under Saudi control had treaties with London, and Ibn Saud was unwilling to provoke the British by pushing into these areas. This did not sit well with the Ikwhan, who had been taught that all non-Wahhabis were infidels. Tensions finally boiled over when the Ikwhan rebelled in 1927. After two years of fighting, they were suppressed by Ibn Saud in the Battle of Sabilla in March 1929.
Ibn Saud was said to be very close to his paternal aunt, Jawhara bint Faisal. From a young age, she ingrained in him a strong sense of family destiny and motivated him to regain the lost glory of the House of Saud. During the years when the Saud family were living almost as refugees in Kuwait, Jawhara bint Faisal frequently recounted the deeds of his ancestors to Abdulaziz and exhorted him not to be content with the existing situation. She was instrumental in making him decide to return to Najd from Kuwait and regain the territories of his family. She was well educated in Islam, in Arab custom and in tribal and clan relationships. She remained among the king's most trusted and influential advisors all her life. Ibn Saud asked her about the experiences of past rulers and the historical allegiance and the roles of tribes and individuals. Jawhara was also deeply respected by the king's children. Ibn Saud visited her daily until she died around 1930.
On 23 September 1932, Ibn Saud formally united the Nejd and Hejaz into the Kingdom of Saudi Arabia, with himself as its king. He transferred his court to Murabba Palace from the Masmak Fort in 1938 and the palace remained his residence and the seat of government until his death in 1953.
He appointed his second son Prince Saud heir to the Saudi throne in 1933. He had many quarrels with his elder brother Muhammad bin Abdul Rahman as to who should be appointed heir. Muhammad wanted his son Khalid to be designated the heir. His eldest son was Turki Al Awwal, who was the Crown Prince of the Kingdoms of Nejd and Hejaz, but unfortunately Turki died at the age of 18, predeceasing his father. After Turki, his younger full-brother was appointed Crown Prince. Had Turki not died, he would have been the Crown Prince. Ibn Saud had 45 sons, of which 36 survived to adulthood. Ten of his sons were capable enough to be candidates for the succession. They were Saud, Faisal, Muhammad, Khalid, Fahd, Abdullah, Sultan, Nayef, Salman and Muqrin. Of these ten, only six became king. Muhammad, Sultan, Nayef and Muqrin were crown Prince but never succeeded the throne. Muhammad resigned from the post, Sultan and Nayef predeceased King Abdullah, and Muqrin was removed from the post.
Ibn Saud positioned Saudi Arabia as neutral in World War II, but was generally considered to favor the Allies. However, in 1938, when an attack on a main British pipeline in the Kingdom of Iraq was found to be connected to the German Ambassador, Fritz Grobba, Ibn Saud provided Grobba with refuge. It was reported that he had been disfavoring the British as of 1937.
The other meeting was with British Prime Minister Winston Churchill in the Grand Hotel du Lac on the shores of the Fayyoun Oasis, fifty miles south of Cairo, in February 1945. However, Saudis report that the meeting heavily focused on the Palestine Problem and was unproductive in terms of its outcomes, in contrast to that with Roosevelt.
In 1948, Ibn Saud participated in the Arab-Israeli War, but Saudi Arabia's contribution was generally considered token.
While most of the royal family desired luxuries such as gardens, splendid cars, and palaces, Ibn Saud wanted a royal railway from the Persian Gulf to Riyadh and then an extension to Jeddah. This was regarded by all of his advisers living in the country as an old man's folly. Eventually, ARAMCO built the railway, at a cost of $70 million, drawn from the King's oil royalties. It was completed in 1951 and was used commercially after the king's death. It enabled Riyadh to grow into a relatively modern city. But when a paved road was built in 1962, the railway lost its traffic.
In October 1953, Ibn Saud was seriously ill due to heart disease. He died in his sleep of a heart attack at the palace of Prince Faisal in Ta'if on 9 November 1953 (2 Rabīʿ al-Awwal 1373 AH) at the age of 78. Prince Faisal was at his side. Funeral prayer was performed at Al Hawiya in Ta'if. His body was brought to Riyadh where he was buried in Al Oud cemetery.