Wikipedia
Al-Rahba (/ ALA-LC: ar-Raḥbah, sometimes spelled Raḥabah), also known as Qal'at ar-Rahba, which translates as the "Citadel of al-Rahba", is a medieval Arab–Islamic fortress in Syria. It is located off the western banks of the Euphrates River, adjacent to the city of Mayadin and southeast of Dayr az-Zawr. Situated atop a mound with an elevation of , al-Rahba oversees the Syrian Desert steppe and historically guarded the Euphrates valley. It has been described as "a fortress within a fortress"; it consists of an inner keep measuring , protected by an enclosure measuring . Al-Rahba is largely in ruins today as a result of erosion.
The original site, which was known as "Rahbat Malik ibn Tawk" after its Abbasid namesake and founder, was located along the Euphrates. It was viewed by Muslim armies, caravans and travelers as the key to Syria from Iraq and sometimes vice versa. Bedouin tribes often took control of it and used it as a launching point for invasions of northern Syria. Because of its strategic location, al-Rahba was frequently fought over by Muslim powers, including local lords, the Hamdanids, the Uqaylids, the Mirdasids and the Seljuks, among others. Rahbat Malik ibn Tawk was destroyed in an earthquake in 1157.
A few years later, the current fortress was built close to the desert edge by the Zengid– Ayyubid lord Shirkuh. The latter's descendants held al-Rahba as a hereditary fief granted by Saladin until 1264. One of them, Shirkuh II, oversaw a third major reconstruction in 1207. Through the early Mamluk era (late 13th–14th centuries), the fortress was continuously restored and strengthened as a result of frequent sieges by the Ilkhanid Mongols of Iraq. Al-Rahba was the most important Mamluk fortress along the Euphrates, an administrative center and the terminal stop on the sultanate's postal route. It fell into disuse during Ottoman rule (1517–1918) and from then until the early 20th century, the fortress primarily served as a shelter for local shepherds and their flocks. Excavations were carried out at the site between 1976 and 1981.