The Quraysh (قُرَيْشٌ) were a grouping of Arab clans that historically inhabited and controlled the city of Mecca and its Kaaba. The Islamic prophet Muhammad was born into the Hashim clan of the tribe. Despite this, many of the Quraysh staunchly opposed Muhammad, until converting to Islam en masse in 630 CE. Afterwards, leadership of the Muslim community traditionally passed to a member of the Quraysh, as was the case with the Rashidun, Umayyad, Abbasid, and purportedly the Fatimid caliphates.
Sources differ as to the etymology of Quraysh, with one theory holding that it was the diminutive form of qirsh (shark). The 9th-century genealogist Hisham ibn al-Kalbi asserted that there was no eponymous founder of Quraysh; rather, the name stemmed from taqarrush, an Arabic word meaning "a coming together" or "association". The Quraysh gained their name when Qusayy ibn Kilab, a sixth-generation descendant of Fihr ibn Malik, gathered together his kinsmen and took control of the Ka'aba. Prior to this, Fihr's offspring lived in scattered, nomadic groups among their Kinana relatives. The nisba or surname of the Quraysh is Qurashī, though in the early centuries of the Islamic Ummah, most Qurayshi tribesmen were denoted by their specific clan instead of the tribe. Later, particularly after the 13th century, claimants of Qurayshi descent used the Qurashī surname.
The Quraysh's progenitor was Fihr ibn Malik, whose full genealogy, according to traditional Arab sources, was the following: Fihr ibn Mālik ibn al-Naḍr ibn Kināna ibn Khuzayma ibn Mudrika ibn Ilyās ibn Muḍar ibn Nizār ibn Maʿadd ibn ʿAdnān. Thus, Fihr belonged to the Kinana tribe and his descent is traced to Adnan the Ishmaelite, the semi-legendary father of the "northern Arabs". According to the traditional sources, Fihr led the warriors of Kinana and Khuzayma in defense of the Ka'ba, at the time a major pagan sanctuary in Mecca, against tribes from Yemen; however, the sanctuary and the privileges associated with it continued to be in the hands of the Yemeni Khuza'a tribe.