Berkyaruq

Map of the Seljuk Empire at the death of Malik-Shah I in 1092

Although Berkyaruq was generally supported by the Nizamiyya, the modern historian Clifford Edmund Bosworth states that "this does not necessarily imply that the Nizamiyya had a collective policy, for none of the sons of Nizam al-Mulk was his father's equal in ability, and opportunism and personal factors seem often to have swayed them".[15] The Nizamiyya were most importantly looking to seek vengeance against Taj al-Mulk, who was believed to have been behind the death of his rival Nizam al-Mulk (which according to modern historian Andrew Peacock, was probably partly true).[12][15][16] A battle took place between the two factions in January 1093, resulting in the defeat of Mahmud's supporters and the capture of Taj al-Mulk. Berkyaruq, aware of Taj al-Mulk's bureaucratic prowess, was willing to make him his vizier.[16] Taj al-Mulk had even managed to appease a section of the Nizamiyya through bribery. Still, this was not enough: the Nizamiyya, thirsty for revenge, secured his execution on 12 February.[16][17] Terken Khatun soon summoned the Seljuk prince Ismail ibn Yaquti to attack Berkyaruq. Although the former had raised an army of Turkoman from Azerbaijan and Arran, he was defeated and executed by Berkyaruq's atabeg Gumush-Tegin.[17] Terken Khatun then tried to reach out to Tutush, but suddenly died in 1094, with her sickly son Mahmud dying a month later.[12][17]

Map of Khurasan and Transoxiana

Berkyaruq also had to deal with his uncle Tutush, who invaded the Jazira and western Iran, seizing the city of Ray. He was, however, killed by Berkyaruq's forces near the same city on 25 February 1095.[12][9] Berkyaruq thus managed to consolidate his authority in western Iran and Iraq, and was also acknowledged as the sultan by al-Mustazhir.[12][10] During the chaos that ensued, Malik-Shah's brother Arghun Arslan conquered most of Khurasan (except the city of Nishapur), attempting to establish his own principality in the province. Berkyaruq first sent an army under his uncle Bori-Bars ibn Alp-Arslan in 1095 to conquer Khurasan, but the latter was captured and killed. He sent a second army under his half-brother Ahmad Sanjar in 1097, but before anything occurred Arghun Arslan was killed by one of his own ghulams, due to his brutal treatment of his subjects. Berkyaruq appointed Sanjar as the vassal ruler (malik) of Khurasan, giving him his own atabeg (Amir Qumaj) and vizier (al-Tughrai).[18][19][20]

Berkyaruq then led an expedition as far east as Tirmidh, where he confirmed the Qarakhanids Sulayman-tegin and Mahmud-tegin as the vassal rulers of Transoxiana.[21] He also appointed Qutb al-Din Muhammad as the new governor of the Central Asian region of Khwarazm, thus marking the start of the Khwarazmian dynasty.[22][23] He spent seven months in the city of Balkh, and then returned to the west.[24] However, after leaving his eastern possessions, the area was plunged into a series of revolts, including one by the Seljuk prince Dawlatshah. The name of Berkyaruq started to get excluded from the coins struck at Nishapur, which testifies to the slow disintegration of his rule in Khurasan. Preoccupied by continuous internal issues, Berkyaruq was unavailable to respond to the advent of the First Crusade in Syria in 1097. The crusaders besieged Antioch and sacked Ma'arrat al-Nu'man. Furthermore, Berkyaruq had little reason to help the Seljuks of Syria, who fought amongst themselves, dividing the country. The northern part was ruled by Fakhr al-Mulk Radwan, and the southern part by Shams al-Muluk Duqaq. When the Crusaders entered Syria, Ridwan shifted his allegiance from Berkyaruq to the Fatimid Caliphate.[21]

Investiture scene of Muhammad I Tapar, from the 14th-century book Jami' al-tawarikh

The most difficult challenge that Berkyaruq faced was the rebellion of his half-brother Muhammad in 1098 or 1099. The rebellion had been encouraged by Nizam al-Mulk's son Mu'ayyid al-Mulk, who had formerly served Berkyaruq and played a key-role in the defeat of Tutush. After his dismissal by Berkyaruq, he entered into the service of Muhammad, who appointed him as his vizier. Mu'ayyid al-Mulk made use of his newfound position to exact vengeance on his rivals, which was made easier because Muhammad had yet to reach adulthood (approximately 17 years old at the time). The Nizamiyya and the prominent families of Isfahan also joined Muhammad, stopping Berkyaruq from entering the city.[25] The rebellion was launched from Muhammad's base at the city of Ganja in Arran, which had been given to him as an iqta' (land grant) by Berkyaruq back in 1093.[26]

Muhammad's capture of Ray exposed the vulnerability of Berkyaruq's realm. Sa'd al-Dawla Gawhara'in, the shihna (military administrator) of Baghdad, soon joined Muhammad, which implies that the city was also added to his domain. Nevertheless, the five-year war continued to be indecisive, with Baghdad repeatedly changing hands. Even with the support of Sanjar (who despised Berkyaruq), Muhammad was unable to defeat his rival. Berkyaruq's authority continued to weaken, and by 1104, with his treasury exhausted, he was forced to sue for peace.[27] A treaty was subsequently made, which acknowledged Muhammad as the ruler of southern Iraq, northern Iran, the Diyar Bakr, Mosul and Syria, while Berkyaruq was acknowledged as the ruler of the rest of Iran (including Isfahan) and Baghdad. The treaty, however, did most likely not display the true circumstances of the situation. The following year (1105), there were no coin mints citing the name of Berkyaruq in the central Islamic lands.[28] En route to Isfahan, he died of tuberculosis at the age of 25 near the town of Borujerd, and was succeeded by his infant son Malik-Shah II.[29] Baghdad was subsequently captured by Muhammad, who had Malik-Shah II killed.[28]