The Abbasids, a powerful Arabian family related to the Prophet Muhammad, acquired the large castle, known as al-Humayma, along the Red Sea trade routes between Damascus, the Umayyad capital in Syria, and Islamic centers on the Arabian Peninsula circa 700. They occupied the site until 749 when they established themselves as Caliphs in Baghdad.On one plaque, a figure stands frontally with his head and feet in profile. Clad in a mail apron and holding a long spear, his headgear resembles armor from Central Asia, possibly connecting al-Humayma to the Abbasid power base there. On each of the other two plaques, an enthroned figure with bouffant hair wears a diadem around his head. Clad in a lavish Persian-style tunic over blousy pantaloons, he sits formally on his throne, rigidly holding a vertical staff. The plaques may have decorated a piece of furniture or a chest. The pieces were excavated in an elaborate room decorated with frescoes across a courtyard from the main entrance to the palace complex that may have been a reception hall. The ivories are discolored as a result of the fire that destroyed the site after the Abbasids left, possibly in the eighth century.