Hashemite traditionally refers to those belonging to the Banu Hashim, or clan of Hashim, a clan within the larger Quraish tribe, of which Muhammad was a member. It also refers to an Arab dynasty whose original strength stemmed from the network of tribal alliances and blood loyalties in the Hejaz region of Arabia, along the Red Sea.
The Hashemites trace their ancestry from Hashim (died about 500), the great-grandfather of the prophet Muhammad. The early history of the Hashemites saw them in a continuous struggle against the Umayyads for control over who would be the caliph or sucessor to Muhammad. The Umayyads were of the same tribe as the Hashemites, but a different clan. This rivalry eventually would lead to the split between the Sunni and Shia. After the overthrow of the Umayyads, the Abbasids would present themselves as representitives of the Hashmites, as they claimed descent from Abbas, an uncle of Muhammad.
From the 10th century onwards, the Sharif (religious leader) of Mecca and its Emir was by traditional agreement a Hashemite. Before World War I Husain ibn Ali of the Hashemite Dhawu-'Awn clan ruled the Hejaz on behalf of the Ottoman sultan. For some time it had been the practice of the Sublime Porte to appoint the Emir of Mecca from among a select group of candidates. In 1908, Husain ibn Ali was appointed Emir of Mecca. He found himself increasingly at odds with the Young Turks in control at Constantinople, while he strove to secure his family's position as hereditary Emirs. Between 1917 and 1925, after the collapse of Ottoman power, he ruled an independent Hejaz, of which he proclaimed himself king, with the tacit support of the British Foreign Office. His chief rival in the Arabian peninsula was a tribal warlord named Ibn Saud, who annexed the Hejaz and set his own son Faisal as governor.
Hussein's two politically active sons were Abdullah and Faisal, later to become the kings, respectively, of Transjordan and Iraq. The Hashemite Kingdom of Iraq lasted from 1921 to 1958, and a line of Hashemite kings have been ruling Transjordan, now Jordan, since 1921.
According to King Hussein's website, the following description is given of the Hashemite coat of arms:
''The crown symbolizes the system of monarchy. The sash upon which the crown is placed symbolizes the Hashemite throne. Its scarlet color represents sacrifice, while the white inner background symbolizes purity.
''The two flags are the flags of the Great Arab Revolt. The eagle in the center of the coat of arms symbolizes power, might and loftiness. The eagle is perched on the globe, and his wings touch the two flags of the Great Arab Revolt. The blue color of the globe symbolizes the spread of Islam across the world.
''The bronze shield in front of the globe represents the defense of truth and right in the world. The spears, swords, bows and arrows are traditional Arab weapons.
''Below the shield to the left are three branches of wheat, and to the right is a palm branch. Stretching down from between the wheat and palm branches is the highest Jordanian medal, the decorative order of al-Nahda.
''Above the al-Nahda medal are three phrases inscribed on a golden ribbon. In the middle:” King of the Hashemite Kingdom of Jordan.” To the right:” Al-Hussein bin Talal bin Aoun” (Aoun, one of the Hashemite patriarchs, was great great-grandfather of Sherif Hussein).