It was viewed by Muslim armies, caravans and travelers as the key to Syria from Iraq and sometimes vice versa. The Mongols damaged it, but were unable to capture it, one of the few such castles.
Much of the current structure dates back to its construction by the Ayyubid lord, Shirkuh II, in 1207.
Al-Rahba (/ALA-LC: ar-Raḥba, 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 42 kilometers (26mi) southeast of Dayr az-Zawr. Situated atop a mound with an elevation of 244 meters (801ft), 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 60 by 30 meters (197ft ×98ft), protected by an enclosure measuring 270 by 95 meters (886ft ×312ft). 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.
Throughout Islamic history, al-Rahba was considered, in the words of the 14th-century traveler Ibn Batuta, 'the end of Iraq and the beginning of al-Sham [Syria]'. The fortress is located about 4 kilometers (2.5mi) southwest of the Euphrates River, 1 kilometer (0.62mi) southwest of the modern Syrian city of Mayadin, and 42 kilometers (26mi) southeast of Dayr az-Zawr, capital of the Dayr az-Zawr Governorate, of which al-Rahba is part. According to the 13th-century geographer Yaqut al-Hamawi, the site's name, al-raḥba, translates from Arabic as the 'flat part of a wadi, where the water collects'; al-Rahba's original location was on the western bank of the Euphrates. The current fortress is situated on an artificial mound detached from the plateau of the Syrian Desert to its west. Its elevation is 244 meters (801ft) above sea level.
According to historian Thierry Bianquis, 'Hardly anything definite is known about the history of the town [al-Rahba] before the Muslim era.' Medieval Talmudic and Syriac writers (such as Michael the Syrian and Bar Hebraeus) identified it with the Biblical town of Rehobot han-Nahar ('Rehobot by the river [Euphrates]'). Some medieval Muslim historians, among them al-Tabari, have written that it was a place called 'Furda' or 'Furdat Nu'm', named after a monastery that supposedly existed in its vicinity called 'Dayr Nu'm'. However, the 9th-century Persian historian al-Baladhuri asserts that there was 'no trace that ar-Rahba... was an old city', and that it was first founded by the Abbasid general Malik ibn Tawk during the reign of Caliph al-Ma'mun (813–833 CE). As such, the fortress town was often referred to as 'Rahbat Malik ibn Tawk' by Muslim historians. According to Syrian historian Suhayl Zakkar, al-Rahba held significant strategic value as it was 'the key to Syria and sometimes to Iraq' and it was the first stop for Syria-bound caravans coming from Iraq. From al-Rahba, travelers, caravans and armies could proceed northwestward along the Euphrates route to Aleppo or traverse the desert route to Damascus. Because of its strategic value, it was frequently fought over by rival Muslim powers. Bedouin tribes in particular used al-Rahba as a main launch point for invasions of northern Syria, and as a safe haven and marketplace. Malik ibn Tawk served as its first lord, and after his death in 873, he was succeeded by his son Ahmad. The latter was expelled following al-Rahba's capture in 883 by the Abbasid lord of al-Anbar, Muhammad ibn Abi'l-Saj. By the 10th century, al-Rahba had become a large town.
In 903, the Qarmatian leader al-Husayn ibn Zikrawayh was imprisoned in al-Rahba before being transferred to Caliph al-Mustakfi's custody in Raqqa. At the time, al-Rahba was the center of the Euphrates province and headquarters of its governor, Ibn Sima. Al-Husayn was executed, prompting his partisans from the Banu Ullays tribe to submit to Ibn Sima in al-Rahba in early 904. However, shortly after, they turned against Ibn Sima, whose forces routed them in an ambush in al-Rahba's environs in August. Following further battles, Ibn Sima received another round of surrenders by Qarmatian chieftains and da'is (Ismaili religious leaders). In March 928, the Qarmatians under Abu Tahir al-Jannabi conquered al-Rahba and massacred scores of its inhabitants. Its residents faced hardships for several more years due to civil strife in the surrounding region. Peace was established in 942 with the arrival of an Abbasid commander named Adl who was dispatched by Bajkam, the strongman of the Baghdad-based caliphate. Adl subsequently became governor of the Euphrates and Khabur valley regions.
Al-Rahba came under Hamdanid rule a few years later, becoming part of the Euphrates district (tariq al-Furat) of the Mosul-based emirate. At the time, the town was described by the Persian geographer al-Istakhri, as being larger than the ancient Circesium on the opposite side of the Euphrates. The lord of al-Rahba, Jaman, rebelled against the Hamdanid emir of Mosul, Nasir al-Dawla (r.929–968/9). Jaman fled the town and drowned in the Euphrates, but not before al-Rahba was heavily damaged in the rebellion's suppression. Nasir al-Dawla granted his favored son, Abu'l-Muzzafar Hamdan, control of al-Rahba, its district of Diyar Mudar, and the district's revenues.
Nasir al-Dawla's sons contested control of al-Rahba in the aftermath of their father's deposition in 969. It ultimately passed to his son Abu Taghlib when his brother and subordinate commander, Hibat-Allah, captured it from Hamdan in a surprise attack. Abu Taghlib had al-Rahba's walls rebuilt. He restored al-Rahba to Hamdan to preempt the possibility of his Buyid enemy, Izz al-Dawla al-Bakhtiyar, forming an alliance with Hamdan to undermine Abu Taghlib. The Hamdanids lost control of al-Rahba in 978, after which it was captured by the Buyid emir 'Adud al-Dawla (r.949–983). In 991, al-Rahba's inhabitants requested and received a governor assigned by 'Adud's son, Emir Baha' al-Dawla (r.988–1012). The town was described by Jerusalemite geographer al-Muqaddasi in the late 10th century as being the center of the Euphrates district, located on the edge of the desert, having a semi-circular layout and being defended by a strong fortress. He also noted that the wider vicinity was characterized by highly irrigated and productive lands, with abundant date palms and quince groves.
In the early 11th century, control of al-Rahba was contested between the Uqaylids of Mosul and the Fatimids of Egypt. Preceding this conflict, the Fatimid caliph al-Hakim appointed a member of the Al Khafajah tribe, Abu Ali ib...