Masjid al-Haram in the context of "King of Saudi Arabia"

Islam is an Abrahamic monotheistic religion based on the Quran and the teachings of Muhammad. Adherents of Islam are called Muslims, who are estimated to number 2 billion worldwide and are the world's second-largest religious population, after Christianity.

Muslims believe that there is a primordial faith that was revealed many times through earlier prophets and messengers, including Adam, Noah, Abraham, Moses, and Jesus, and they believe that Islam is the universal and complete version of this faith. Muslims consider the Quran to be the verbatim word of God and the unaltered, final revelation. Alongside the Quran, Muslims also believe in previous revelations, such as the Tawrat (the Torah), the Zabur (Psalms), and the Injil (Gospel). They believe that Muhammad is the main and final of God's prophets, through whom the religion was completed. The teachings and normative examples of Muhammad, called the Sunnah, documented in accounts called the hadith, provide a constitutional model for Muslims. Islam is based on the belief in the oneness and uniqueness of God (tawhid), and belief in an afterlife (akhirah) with the Last Judgment—wherein the righteous will be rewarded in paradise (jannah) and the unrighteous will be punished in hell (jahannam). The Five Pillars, considered obligatory acts of worship, are the Islamic oath and creed (shahada), daily prayers (salah), almsgiving (zakat), fasting (sawm) in the month of Ramadan, and a pilgrimage (hajj) to Mecca. Islamic law, sharia, touches on virtually every aspect of life, from banking and finance and welfare to men's and women's roles and the environment. The two main religious festivals are Eid al-Fitr and Eid al-Adha. The three holiest sites in Islam are Masjid al-Haram in Mecca, Prophet's Mosque in Medina, and al-Aqsa Mosque in Jerusalem.

The term "Holy Land" is used to collectively denote areas of the Southern Levant that hold great significance in the Abrahamic religions, primarily because of their association with people and events featured in the Bible. It is traditionally synonymous with what is known as the Land of Israel (Zion) or the Promised Land in a biblical or religious context, or as Canaan or Palestine in a secular or geographic context—referring to a region that is mostly between the Mediterranean Sea and the Jordan River. Today, it chiefly overlaps with the combined territory of the modern states of Israel and Palestine. Most notable among the religions that tie substantial spiritual value to the Holy Land are Judaism, Christianity, and Islam.

A considerable part of the Holy Land's importance derives from Jerusalem, which is regarded as extremely sacred in and of itself. It is the holiest city in Judaism and Christianity and the third-holiest city in Islam (behind Mecca and Medina in the Arabian Peninsula). The Temple in Jerusalem, referring to Solomon's Temple and the Second Temple, was the central place of worship for Israelites and Jews and serves as the namesake of the Temple Mount. According to the Bible, Jerusalem was made the capital city of the Kingdom of Israel and Judah under the House of David, thereafter being inherited by the Kingdom of Judah alone. Jesus of Nazareth, first brought to Jerusalem to be presented at the Second Temple shortly after his birth, was also highly active throughout the city during his life as a preacher. In Islamic belief, Isra' and Mi'raj refer to a night journey by Muhammad to the Holy Land, with the supernatural "Buraq" transporting him from Mecca's Masjid al-Haram to Jerusalem's Al-Aqsa Mosque, where he ascended to heaven and met God and past Islamic prophets and messengers; Jerusalem also served as the qibla (direction of Muslim prayers) prior to Mecca's Kaaba.

Mecca, officially Makkah al-Mukarramah, is the holiest city in Islam. It is located in the Hejaz region of western Saudi Arabia and is the capital of Mecca Province. Mecca is considered the birthplace of Islam and the birthplace of the Islamic prophet Muhammad.

It is 70 km (43 mi) inland from Jeddah on the Red Sea, in a narrow valley 277 m (909 ft) above sea level. Its metropolitan population in 2022 was 2.4 million, making it the third–most populated city in Saudi Arabia after Riyadh and Jeddah. The Cave of Hira atop the Jabal al-Nour, just outside the city, is where Muslims believe the Quran was first revealed to Muhammad. Visiting Mecca for the Ḥajj is an obligation upon all able Muslims. The Great Mosque of Mecca, known as the Masjid al-Haram, is home to the Kaaba, believed by Muslims to have been built by Abraham and Ishmael. It is Islam's holiest site and the direction of prayer (qibla) for all Muslims worldwide. Around 44.5% of the population are Saudi citizens and around 55.5% are Muslim foreigners from other countries. Pilgrims more than triple the population number every year during the Ḥajj pilgrimage, observed in the twelfth Hijri month of Dhūl-Ḥijjah. With over 10.8 million international visitors in 2023, Mecca was one of the ten most visited cities in the world.

The holiest sites in Islam are located in the Middle East. While the significance of most places typically varies depending on the Islamic sect, there is a consensus across all mainstream branches of the religion that affirms three cities as having the highest degree of holiness, in descending order: Mecca, Medina, and Jerusalem. Mecca's Al-Masjid al-Haram (including the Kaaba), Al-Masjid an-Nabawi in Medina, and Jerusalem's Al-Aqsa Mosque are all revered by Muslims as sites of great importance.

After the consensus on the first three sites as well as further sites associated with the family of Muhammad, there is a divergence between Sunni Muslims and Shia Muslims on the designation of additional holy sites. Even within each sect, there are disputes as to whether any uniquely holy cities exist apart from the aforementioned three. For Sunnis that argue that there are, sites associated with the Rashidun, other Companions of Muhammad, and Biblical prophets often hold a high level of significance (see holiest sites in Sunni Islam). In particular, the Umayyad Mosque in the city of Damascus and the Ibrahimi Mosque in the city of Hebron have held interchangeable significance as the fourth and fifth-holiest Islamic sites, respectively, for many Sunni Muslims. For Shias, sites associated with the Imamah hold a high level of significance (see holiest sites in Shia Islam).

The Prophet's Mosque (Arabic: ٱلْمَسْجِد ٱلنَّبَوِي‎, romanized: al-Masjid al-Nabawī, lit. 'Mosque of the Prophet') is the second mosque built by the Islamic prophet Muhammad in Medina, after the Quba Mosque, as well as the second largest mosque and holiest site in Islam, after the Masjid al-Haram in Mecca, in the Saudi region of the Hejaz. The mosque is located at the heart of Medina, and is a major site of pilgrimage that falls under the purview of the Custodian of the Two Holy Mosques (a royal style used by the King of Saudi Arabia.)

Muhammad himself was involved in the construction of the mosque. At the time, the mosque's land belonged to two young orphans, Sahl and Suhayl, and when they learned that Muhammad wished to acquire their land to erect a mosque, they went to Muhammad and offered the land to him as a gift; Muhammad insisted on paying a price for the land because they were orphaned children. The price agreed upon was paid by Abu Ayyub al-Ansari, who thus became the endower or donor (Arabic: وَاقِف, romanized: wāqif) of the mosque, on behalf or in favor of Muhammad. al-Ansari also accommodated Muhammad upon his arrival at Medina in 622.

A congregational mosque or Friday mosque (Arabic: مَسْجِد جَامِع, romanized: masjid jāmi‘, or simply جَامِع, jāmi‘; Turkish: Cami), or sometimes great mosque or grand mosque (جامع كبير, jāmi‘ kabir; Ulu Cami), is a mosque for hosting the Friday noon prayers known as jumu'ah. It can also host the Eid prayers in situations when there is no musalla or eidgah available nearby to host the prayers. In early Islamic history, the number of congregational mosques in one city was strictly limited. As cities and populations grew over time, it became more common for many mosques to host Friday prayers in the same area. In early centuries, the congregational mosque was also a center of social and public life, hosting various other activities in addition to prayers, such as judicial and educational functions.

The Kaaba (Arabic: الكعبة, romanized: al-Kaʿba, lit. 'the Cube'), also spelled Kaʽba, Kaʽbah or Kabah, sometimes referred to as al-Kaʽba al-Musharrafa (Arabic: الكعبة المشرفة, lit. 'the Honored Ka'ba'), is a stone building at the center of Islam's most important mosque and holiest site, the Masjid al-Haram in Mecca, Saudi Arabia. It is considered by Muslims to be the Baytullah (Arabic: بيت اللَّٰه, lit. 'House of God') and determines the qibla (Arabic: قبلة, lit. 'direction of prayer') for Muslims around the world.

According to Islamic tradition, the Kaaba was rebuilt several times throughout history, most famously by Ibrahim and his son Ismail, when he returned to the valley of Mecca several years after leaving his wife Hajar and Ismail there upon Allah's command. The current structure was built after the original building was damaged by a fire during the siege of Mecca by the Umayyads in 683 CE. Circling the Kaaba seven times counterclockwise, known as Tawaf (Arabic: طواف, romanized: tawaaf), is a Fard rite for the completion of the Hajj and Umrah pilgrimages. The area around the Kaaba where pilgrims walk is called the Mataaf.

Muslims, including Shia, Sunni, Ibadi and other branches, agree on two holiest sites in Islam being the Masjid al-Haram (including the Kaaba) in Mecca; the Masjid an-Nabawi in Medina.

Sites associated with the Islamic prophet Muhammad, his daughter Fatima and son-in-law Ali, the respective Shia Imams descended from them and their family members (collectively referred to as Ahl al-Bayt) are considered holy by the different Shia Muslim sects. Karbala and Najaf in Iraq are two of holiest cities revered by all Shia sects. Additionally, Mashhad and Qom in Iran are two of the holiest cities to Twelver Shia, the largest Shia sect.