Anno Hegirae in the context of "Hajj"

The Abbasid Caliphate or Abbasid Empire was the third Islamic caliphate, founded by a descendant of Muhammad's uncle, Abbas ibn Abd al-Muttalib (566–653 CE), from whom the dynasty derives its name. The preceding Umayyad Caliphate was overthrown by the Abbasid Revolution in 750 CE (132 AH), after which the Abbasids ruled as caliphs from their base in Iraq, with Baghdad as their capital for most of their history.

The Abbasid Revolution had its origins and first successes in the easterly region of Khurasan, far from the Levantine center of Umayyad influence. The Abbasids first centered their government in Kufa, Iraq, but in 762 the second caliph al-Mansur founded the city of Baghdad and made it the capital. Baghdad became a center of science, culture, arts, and invention, ushering in what became known as the Golden Age of Islam. Baghdad housed several key academic institutions, such as the House of Wisdom, and along with its multi-ethnic and multi-religious population, made the city famous as a centre of learning across the world. The Abbasid period was marked by the use of bureaucrats in the government, including the vizier, as well as an in the ummah (Muslim community) and among the political elites.

Wahhabism is a Salafi revivalist movement within Sunni Islam named after the 18th-century Hanbali scholar Muhammad ibn Abd al-Wahhab. It was initially established in the central Arabian region of Najd and later spread to other parts of the Arabian Peninsula, and was the official policy of Saudi Arabia until 2022. Despite being founded on the principles of Sunni Islam, the Hanbalite scholars Ibn Taimiyya and Ibn al-Qayyim in particular, Wahhabism may also refer to doctrinal differences distinct from other forms of Sunni Islam. Non-Wahhabi Sunnis also have compared Wahhabism to the belief of the Kharijites and loyalist monarchism despite the two belief systems being contradictory to each other.

The Wahhabi movement staunchly denounced rituals related to the veneration of Muslim saints and pilgrimages to their tombs and shrines, which were widespread amongst the people of Najd. Ibn 'Abd al-Wahhab and his followers were highly inspired by the Hanbali scholar Ibn Taymiyya (1263–1328 CE/AH 661–728) who advocated a return to the purity of the first three generations (salaf) to rid Muslims of bid'a (innovation) and regarded his works as core scholarly references in theology. While being influenced by Hanbali school, the movement repudiated taqlid to legal authorities, including oft-cited scholars such as Ibn Taymiyya and Ibn Qayyim (d. 1350 CE/AH 751).

The Sanaa palimpsest (also Ṣanʽā’ 1 or DAM 01-27.1) or Sanaa Quran is one of the oldest Quranic manuscripts in existence. Part of a sizable cache of Quranic and non-Quranic fragments discovered in Yemen during a 1972 restoration of the Great Mosque of Sanaa, the manuscript was identified as a palimpsest Quran in 1981 as it is written on parchment and comprises two layers of text.

• The upper text entirely conforms to the standard Uthmanic Quran in text and in the standard order of surahs (chapters).
• The lower text, which was erased and written over by the upper text, but can still be read with the help of ultraviolet light and computer processing, contains many variations from the standard text. The sequence of its chapters corresponds to no known Quranic order.

A partial reconstruction of the lower text was published in 2012, and a reconstruction of the legible portions of both lower and upper texts of the 38 folios in the Sana'a House of Manuscripts was published in 2017 utilising post-processed digital images of the lower text. A radiocarbon analysis has dated the parchment of one of the detached leaves sold at auction, and hence its lower text, to between 578 AD (44 BH) and 669 AD (49 AH) with a 95% accuracy. The earliest leaves have been tested at three laboratories and dated to 388–535 AD. Other folios have similar early dates.

The Battle of Badr or sometimes called The Raid of Badr (Arabic: غَزْوَةُ بَدْرٍ [ɣazwatu badr]; Ghazwahu Badr), also referred to as The Day of the Criterion (Arabic: يَوْمُ الْفُرْقَانْ, Arabic pronunciation: [jawm'ul fur'qaːn]; Yawm al-Furqan) in the Qur'an and by Muslims, was fought on 13 March 624 CE (17 Ramadan, 2 AH), near the present-day city of Badr, Al Madinah Province in Saudi Arabia. Muhammad, commanding an army of his Sahaba, defeated an army of the Quraysh led by Amr ibn Hishām, better known among Muslims as Abu Jahl. The battle marked the beginning of the six-year war between Muhammad and his tribe. The Battle of Badr took place after five or six unsuccessful attempts by the Muslims to intercept and raid Meccan trade caravans between 623 and early 624 CE.

Muhammad took keen interest in capturing Meccan caravans and their wealth after his migration to Medina. A few days before the battle, when he learnt of a Makkan caravan returning from the Levant led by Abu Sufyan ibn Harb, Muhammad gathered a small expeditionary force to raid it. Abu Sufyan, learning of the Muslim plan to ambush his caravan, changed course and took a longer route away from Muhammad's base at Medina and sent a messenger to Mecca, asking for help. Amr ibn Hisham commanded an army nearly one-thousand strong, approaching Badr and encamping at the sand dune al-'Udwatul Quswa.