Primarily Sunnis in the Arab world reserve the term sharif for descendants of Hasan ibn Ali, while sayyid is used for descendants of Husayn ibn Ali. Both Hasan and Husayn are grandchildren of Muhammad, through the marriage of his cousin Ali and his daughter Fatima. However ever since the post-Hashemite era began, the term sayyid has been used to denote descendants from both Hasan and Husayn. Arab Shiites use the terms sayyid and habib to denote descendants from both Hasan and Husayn; see also ashraf.
From 1201 until the Hejaz was conquered by Ibn Saud in 1925, this family held the office of the Sharīf of Makkah, often also carrying the title and office of King of Hejaz. Descendants now rule the Hashemite Kingdom of Jordan, the name being taken from the Banu Hashim, the sub-tribe of Banu Quraish, to which Muhammad belonged.