Banu Qatadah in the context of "Qatadah ibn Idris"

Hussein bin Ali al-Hashimi (Arabic: ٱلْحُسَيْن بِن عَلِي ٱلْهَاشِمِي, romanized: al-Ḥusayn bin 'Alī al-Hāshimī pronunciation; 1 May 1854 – 4 June 1931) was a Hejazi leader from the Banu Qatadah branch of the Banu Hashim clan who was the Sharif and Emir of Mecca from 1908 and, after proclaiming the Great Arab Revolt against the Ottoman Empire, King of the Hejaz, even if he refused this title, from 1916 to 1924. He proclaimed himself Caliph after the abolition of the Ottoman Caliphate in 1924 and stayed in power until 1925 when Hejaz was invaded by the Sultanate of Nejd. His Caliphate was opposed by the British and French empires, the Zionists and the Wahhabis alike. However, he received support from a large part of the Muslim population of that time and from Mehmed VI. He is usually considered as the father of modern pan-Arabism.

In 1908, in the aftermath of the Young Turk Revolution, Hussein was appointed Sharif of Mecca by the Ottoman sultan Abdul Hamid II. His relationship with the Ottoman government deteriorated after the Committee of Union and Progress took power, particularly because of their policies of Turkification and persecution of ethnic minorities, including Arabs. In 1916, with the promise of British support for Arab independence, although it is debated as to what extent the British were influential in his choice, he proclaimed the Arab Revolt against the Ottoman Empire, accusing the Committee of Union and Progress of violating tenets of Islam and limiting the power of the sultan-caliph. While his armies, led by his sons, were engaged in fighting the Ottoman and German troops in the Middle East, Hussein supported the Armenians during the Armenian genocide and saved up to 4,000 of them. In the aftermath of World War I, Hussein refused to ratify the Treaty of Versailles, in protest of the Balfour Declaration, a document supporting the Jewish settlers in Palestine, and the establishment of British and French mandates in Syria, Iraq, and Palestine. His sons Faisal and Abdullah were made rulers of Iraq and Transjordan respectively in 1921.

The Sharifate of Mecca (Arabic: شرافة مكة, romanized: Sharāfat Makka) or Emirate of Mecca was a state, semi-sovereign for much of its existence, ruled by the Sharif of Mecca. A sharif is a descendant of Hasan ibn Ali, Muhammad's grandson. In Western sources, the prince of Mecca was known as Grand Sherif, but Arabs have always used the appellation "Emir".

The Sharifate existed from about 967 to 1916, when it became the Kingdom of Hejaz. From 1201, the descendants of the Sharifian patriarch Qatada ruled over Mecca, Medina and the Tihamah in unbroken succession until 1925. Originally a Zaydi Shi'ite emirate, the Hasanid Sharifs converted to the Shafi'i rite of Sunni Islam in the late Mamluk or early Ottoman period.

Hussein bin Ali al-Hashimi (Arabic: ٱلْحُسَيْن بِن عَلِي ٱلْهَاشِمِي, romanized: al-Ḥusayn bin 'Alī al-Hāshimī pronunciation; 1 May 1854 – 4 July 1931) was a Hejazi leader from the Banu Qatadah branch of the Banu Hashim clan who was the Sharif and Emir of Mecca from 1908 and, after proclaiming the Great Arab Revolt against the Ottoman Empire, King of the Hejaz, even if he refused this title, from 1916 to 1924. He accepted the Caliphate after delegations from the Hijaz and neighboring regions urged him to assume it, stayed in power until 1925 when Hejaz was invaded by the Sultanate of Nejd. His Caliphate was opposed by the British and French empires, the Zionists and the Wahhabis alike. He received symbolic support from certain Hijazi religious circles and some Arab delegations, but broad Muslim recognition did not materialize. Later Arab nationalist writers sometimes portrayed him as the father of modern pan-Arabism, but some historians argue that the Hashemites were still newer converts to Arabism in 1916 and were not early Arab nationalists.

In 1908, in the aftermath of the Young Turk Revolution, Hussein was appointed Sharif of Mecca by the Ottoman sultan Abdul Hamid II. His relationship with the Ottoman government deteriorated after the Committee of Union and Progress took power, due to CUP efforts to centralize administration in the Hijaz and reduce the Sharif’s traditional autonomy. In 1916, with the promise of British support for Arab independence, although it is debated as to what extent the British were influential in his choice, he revolted against the Ottomans only after attempts to secure hereditary control of the Hijaz through negotiation with the Ottoman government failed, accusing the Committee of Union and Progress of violating tenets of Islam and limiting the power of the sultan-caliph, framing the revolt as a defense of the historic rights of the Hejaz rather than a modern nationalist movement. While his armies, led by his sons, were engaged in fighting the Ottoman and German troops in the Middle East, but the initial stage of the insurrection was carried out entirely with Hijazi forces, and Arabs in Syria and Iraq never actually rose against the Turks. Hussein supported the Armenians during the Armenian genocide and saved up to 4,000 of them. In the aftermath of World War I, Hussein refused to ratify the Treaty of Versailles, in protest of the Balfour Declaration, a document supporting the Jewish settlers in Palestine, and the establishment of British and French mandates in Syria, Iraq, and Palestine. His sons Faisal and Abdullah were made rulers of Iraq and Transjordan respectively in 1921.