After the new Saudi kingdom was formalized in 1932, Faisal became Minister of Foreign Affairs, a position he continued to hold even as King. Faisal also commanded a section of the Saudi forces that took part in the brief Saudi - Yemeni War of 1934, successfully fighting off Yemeni claims over Saudi Arabia's southern provinces.

ARAMCO's development of Saudi oil after World War II quintupled revenue from $10.4 million in 1946 to $56.7 million in 1950. As King Abdul - Aziz's health declined and his leadership became lax, Faisal comprehended the necessity for better economic management. In the summer of 1951, Abdul - Aziz enlarged the government bureaucracy to include many more members of the extended royal family. Faisal's son Abdullah was appointed Minister of Health and Interior.

Upon the accession of Faisal's elder brother, Saud, to the throne in 1953, Faisal was appointed Crown Prince. Saud, however, embarked on a lavish and ill considered spending program that included the construction of a massive royal residence on the outskirts of the capital, Riyadh. He also faced pressure from neighboring Egypt, where Gamal Abdel Nasser had overthrown the monarchy in 1952. Nasser was able to cultivate a group of dissident princes led by Prince Talal who defected to Egypt (Free Princes). Fearing that Saud's financial policies were bringing the state to the brink of collapse, and that his handling of foreign affairs was inept, senior members of the royal family and the religious leadership (the "ulema") pressured Saud into appointing Faisal to the position of prime minister in 1958, giving Faisal wide executive powers. In this new position, Faisal set about cutting spending dramatically in an effort to rescue the state treasury from bankruptcy. This policy of financial prudence was to become a hallmark of his era and earned him a reputation for thriftiness among the populace.

A power struggle ensued thereafter between Saud and Faisal, and on December 18, 1960, Faisal resigned as prime minister in protest, arguing that Saud was frustrating his financial reforms. Saud took back his executive powers and, having induced Talal to return from Egypt, appointed Talal as minister of finance. In 1962, however, Faisal rallied enough support within the royal family to install himself as prime minister for a second time.

During this period as head of the Saudi government, that Faisal, though still not king, established his reputation as a reforming and modernizing figure. He introduced education for women and girls despite the consternation of many conservatives in the religious establishment. To appease the objectors, however, he allowed the female educational curriculum to be written and overseen by members of the religious leadership, a policy which lasted long after Faisal's death. It was also during this time that Faisal formally abolished slavery.

In 1963, Faisal established the country's first television station, though actual broadcasts would not begin for another two years. As with many of his other policies, the move aroused strong objections from the religious and conservative sections of the country. Faisal assured them, however, that Islamic principles of modesty would be strictly observed, and made sure that the broadcasts contained a large amount of religious programming.

The struggle with King Saud continued in the background during this time. Taking advantage of the king's absence from the country for medical reasons in early 1963, Faisal began amassing more power for himself. He removed many of Saud's loyalists from their posts and appointed like minded princes in key military and security positions, such as his brother Abdullah, to whom he gave command of the National Guard in 1962. Upon Saud's return, Faisal demanded that he be made regent and that Saud be reduced to a purely ceremonial role. In this, he had the crucial backing of the ulema, including an edict (or fatwa) issued by the grand mufti of Saudi Arabia, a relative of Faisal's on his mother's side, calling on Saud to accede to his brother's demands. Saud refused, however, and made a last ditch attempt to retake executive powers, leading Faisal to order the National Guard to surround Saud's palace. His loyalists outnumbered and outgunned, Saud relented, and on March 4, 1964, Faisal was appointed regent. A meeting of the elders of the royal family and the ulema was convened later that year, and a second fatwa was decreed by the grand mufti calling on Saud to abdicate the throne in favor of his brother. The royal family supported the fatwa and immediately informed Saud of their decision. Saud, by now shorn of all his powers, agreed, and Faisal was proclaimed king on November 2, 1964. Shortly thereafter, Saud left into exile in Greece.

Upon his ascension, Faisal still viewed the restoration of the country's finances as his main priority. He continued to pursue his conservative financial policies during the first few years of his reign, and his aims of balancing the country's budget eventually succeeded, helped by an increase in oil production.

Faisal embarked on a modernization project that encompassed vast parts of the kingdom and involved various public sector institutions. The pinnacle of his achievements in modernizing the Kingdom was the establishment of a judicial system, a project led and executed by an international lawyer and judge, the former Syrian Minister of Justice, Zafer Moussly.

The improved financial situation allowed Faisal to pursue various reforms and modernization projects. Several universities were established or expanded during his rule, and he continued to send a great number of students to foreign universities, especially in the United States. These students would later form the core of the Saudi civil service.

Many of the country's ministries, government agencies, and welfare programs were begun during Faisal's reign, and he invested heavily in infrastructure. He also introduced policies such as agricultural and industrial subsidies that were later to reach their height under his successors, Khalid and Fahd. In 1964, he issued an edict that all Saudi princes had to school their children inside the country, rather than sending them abroad; this had the effect of making it "fashionable" for upper class families to bring their sons back to study in the Kingdom. Faisal also introduced the country's current system of administrative regions, and laid the foundations for a modern welfare system. In 1970, he established the Ministry of Justice and inaugurated the country's first "five - year plan" for economic development.

Television broadcasts officially began in 1965. In 1966, an especially zealous nephew of Faisal attacked the newly established headquarters of Saudi television but was killed by security personnel. The attacker was the brother of Faisal's future assassin, and the incident is the most widely accepted motive for the murder. Despite the opposition from conservative Saudis to his reforms, however, Faisal continued to pursue modernization while always making sure to couch his policies in Islamic terms.

The 1950s and 1960s saw numerous coups d'état in the region. Muammar al-Gaddafi's coup that overthrew the monarchy in oil rich Libya in 1969 was especially ominous for Saudi Arabia due to the similarity between the two sparsely populated desert countries. As a result, Faisal undertook to build a sophisticated security apparatus and cracked down firmly on dissent. As in all affairs, Faisal justified these policies in Islamic terms. Early in his reign, when faced by demands for a written constitution for the country, Faisal responded that "our constitution is the Quran." In 1969, Faisal ordered the arrest of hundreds of military officers, including some generals, alleging that a military coup was being planned. The arrests were possibly based on a tip from American intelligence, but it is unclear how serious the threat actually was.

Faisal also put down protests by Saudi workers employed by the international oil company, Aramco, in the Eastern Province, and banned the formation of labor unions in 1965. In compensation for these actions, however, Faisal introduced a far reaching labor law with the aim of providing maximum job security for the Saudi workforce. He also introduced pension and social insurance programs for workers despite objections from some of the ulema.

As king, Faisal continued the close alliance with the United States begun by his father, and relied on the U.S. heavily for arming and training his armed forces. Faisal was also anti - Communist. He refused any political ties with the Soviet Union and other Communist bloc countries, professing to see a complete incompatibility between Communism and Islam, and associating Communism with Zionism, which he also criticized sharply.

Faisal also supported monarchist and conservative movements in the Arab world, and sought to counter the influences of socialism and Arab Nationalism in the region by promoting pan - Islamism as an alternative. To that end, he called for the establishment of the Muslim World League, visiting several Muslim countries to advocate the idea. He also engaged in a propaganda and media war with Egypt's pan - Arabist president, Gamal Abdel Nasser, and engaged in a proxy war with Egypt in Yemen that lasted until 1967 (Yemeni Civil War). Faisal never explicitly repudiated pan - Arabism, however, and continued to call for inter - Arab solidarity in broad terms.

Following the death of Nasser in 1970, Faisal drew closer to Egypt's new president, Anwar Sadat, who himself was planning a break with the Soviet Union and a move towards the pro - American camp. During the 1973 Arab - Israeli War, launched by Sadat, Faisal withdrew Saudi oil from world markets, in protest over Western support for Israel during the conflict. This action quadrupled the price of oil and was the primary force behind the 1973 energy crisis. It was to be the defining act of Faisal's career, and gained him lasting prestige among many Arabs and Muslims worldwide. In 1974, he was named Time magazine's Man of the Year, and the financial windfall generated by the crisis fueled the economic boom that occurred in Saudi Arabia after his death. The new oil revenue also allowed Faisal to greatly increase the aid and subsidies begun following the 1967 Arab - Israeli War to Egypt, Syria, and the Palestine Liberation Organization. It is a commonly held belief in Saudi Arabia and the Arab and Muslim world that Faisal's oil boycott was the real cause of his assassination, via a Western conspiracy, his assassin having just returned from the United States.

Faisal also developed a close alliance with Pakistan, where he is regarded highly for his foreign policy and pan - Islamic ideals. He was a very close friend of Zulfikar Ali Bhutto renowned Prime Minister of Pakistan, as well as General Muhammad Zia ul-Haq. Lyallpur, which was then the third largest city and currently is the fifth largest, was renamed Faisalabad (lit. "City of Faisal") in 1979 in his honor. The Faisal Mosque in Islamabad is named after him as well. The main highway in Karachi was renamed Shahrah - e - Faisal and a suburb close to Karachi Airportwas also renamed Shah Faisal Colony. One of the two major air force bases in Pakistan's largest city, Karachi, is named "PAF Base Faisal" in the honour of King Faisal.

On March 25, 1975, Faisal was shot point blank and killed by his half - brother's son, Faisal bin Musaid, who had just come back from the United States. The murder occurred at a majlis (Arabic for "a place for sitting"), an event where the king or leader opens up his residence to the citizens to enter and petition the king.

In the waiting room, Prince Faisal talked with Kuwaiti representatives who were also waiting to meet King Faisal. When the Prince went to embrace him, King Faisal leaned to kiss his nephew in accordance with Saudi culture. At that instant, Prince Faisal took out a pistol and shot him. The first shot hit King Faisal's chin and the second one went through King Faisal's ear. A bodyguard hit Prince Faisal with a sheathed sword. Oil minister Sheikh Yamani yelled repeatedly to not kill Prince Faisal.

King Faisal was quickly sent to the hospital. He was still alive as doctors massaged his heart and gave him a blood transfusion. They were unsuccessful and King Faisal died shortly afterward. Both before and after the assassination the prince was reported to be calm. Following the killing, Riyadh had three days of mourning and all government activities were at a standstill.

Prince Faisal, who was captured directly after the attack, was officially declared insane. But following the trial, a panel of Saudi medical experts decided that Faisal was sane when he gunned the king down. The nation's high religious court convicted him of regicide and sentenced him to execution. The public execution took place June 18, 1975 at 4:30 p.m. -- three hours before sundown — before a throng of thousands at the Al Hukm Palace (Palace of Justice). Despite Faisal's dying request that the life of his assassin be spared, he was beheaded in the public square in Riyadh.

Faisal was buried in Riyadh. His successor, Khalid, wept over his body at his funeral.

Faisal married three times. He only had one wife at a time. The first wife passed away. He divorced his second wife. His last and his most prominent wife was Iffat Al-Thuniyyan. She was raised in Turkey and was a descendant of the Al Saud clan who were taken to Istanbul or Cairo by Egyptian forces in 1818 (First Saudi State). Iffat is credited with being the influence behind many of her late husband's reforms, particularly with regards to women.

The late King's sons have held and continue to hold important positions within the Saudi government. Prince Khalid was the governor of Asir Province in southwestern Saudi Arabia for more than three decades before becoming governor of Makkah Province in 2007. Prince Saud has been the Saudi foreign minister since 1975. Prince Turki served as head of Saudi intelligence, ambassador to the United Kingdom, and later ambassador to the United States.

His sons received exceptional education compared to other princes born to Saudi monarchs. Turki received formal education at prestigious schools in New Jersey, and later attended Georgetown University, while Saud is an alumnus of Princeton.

Faisal's daughter, Princess Haifa, is married to his nephew Bandar bin Sultan, the former long serving Saudi ambassador to the United States and current Saudi national security adviser. Bandar had been all but disowned by his father Sultan at the time due to his perceived inferior lineage. Faisal, however, forced Sultan to recognize Bandar as a legitimate prince by giving Bandar his own daughter's hand in marriage. Another daughter, Lolowah is a prominent activist for women's education in Saudi Arabia.

After his death, Faisal's family established the King Faisal Foundation.