Great Seljuq Empire The Great Seljuq Empire ( Modern Turkish : Büyük Selçuklu Devleti ; ) was a medieval Turko - Persian Sunni Muslim empire , originating from the " Qynyq " branch of Oghuz Turks . The Seljuq Empire controlled a vast area stretching from the Hindu Kush to eastern Anatolia and from Central Asia to the Persian Gulf . From their homelands near the Aral sea , the Seljuqs advanced first into Khorasan and then into mainland Persia before eventually conquering eastern Anatolia . The Seljuq empire was founded by Tughril Beg in 1037 after the efforts by the founder of the Seljuq dynasty , Seljuq Beg , in the first quarter of the 11th century . Seljuq Beg ' s father was in a higher position in the Oghuz Yabgu State , and he gave his name to both the state and the dynasty . The Seljuqs united the fractured political scene of the Eastern Islamic world and played a key role in the first and second crusades . Highly Persianized in culture and language , the Seljuqs also played an important role in the development of the Turko - Persian tradition , even exporting Persian culture to Anatolia . The settlement of Turkic tribes in the northwestern peripheral parts of the empire , for the strategic military purpose of fending off invasions from neighboring states , led to the progressive turkicization of those areas . Founder of the Dynasty . The apical ancestor of the Seljuqs was their beg , Seljuq , who was reputed to have served in the Khazar army , under whom , circa 950 , they migrated to Khwarezm , near the city of Jend , where they converted to Islam . Expansion of the Empire . The Seljuqs were allied with the Persian Samanid Shahs against the Qarakhanids . The Samanids fell to the Qarakhanids in Transoxania ( 992 / 999 ) , however , whereafter the Ghaznavids arose . The Seljuqs became involved in this power struggle in the region before establishing their own independent base . Tugrul and Chagri Beg . Tughril was the grandson of Seljuq and brother of Chaghri , under whom the Seljuks wrested an empire from the Ghaznavid s . Initially the Seljuqs were repulsed by Mahmud and retired to Khwarezm , but Tughril and Chaghri led them to capture Merv and Nishapur ( 1037 ) . Later they repeatedly raided and traded territory with his successors across Khorasan and Balkh and even sacked Ghazni in 1037 . In 1040 at the Battle of Dandanaqan , they decisively defeated Mas ' ud I of the Ghaznavids , forcing him to abandon most of his western territories to the Seljuqs . In 1055 , Tughril captured Baghdad from the Shi ' a Buyids under a commission from the Abbassid s . Alp Arslan . Alp Arslan , the son of Chaghri Beg , expanded significantly upon Tughril ' s holdings by adding Armenia and Georgia in 1064 and invading the Byzantine Empire in 1068 , from which he annexed almost all of Anatolia . Arslan ' s decisive victory at the Battle of Manzikert in 1071 effectively neutralized the Byzantine threat . He authorized his Turkmen generals to carve their own principalities out of formerly Byzantine Anatolia , as atabeg s loyal to him . Within two years the Turkmens had established control as far as the Aegean Sea under numerous " beghliks " ( modern Turkish beyliks ) : the Saltukids in Northeastern Anatolia , Mengujekids in Eastern Anatolia , Artuqid s in Southeastern Anatolia , Danishmend is in Central Anatolia , Rum Seljuqs ( Beghlik of Suleyman , which later moved to Central Anatolia ) in Western Anatolia , and the Beylik of Tzachas of Smyrna in İzmir ( Smyrna ) . Malik Shah I . Under Alp Arslan ' s successor , Malik Shah , and his two Persian viziers , Nizām al - Mulk and Tāj al - Mulk , the Seljuq state expanded in various directions , to the former Iranian border of the days before the Arab invasion , so that it soon bordered China in the East and the Byzantines in the West . Malikshāh moved the capital from Rey to Isfahan . The Iqta military system and the Nizāmīyyah University at Baghdad were established by Nizām al - Mulk , and the reign of Malikshāh was reckoned the golden age of " Great Seljuq " . The Abbasid Caliph titled him " The Sultan of the East and West " in 1087 . The Assassins ( " Hashshashin " ) of Hassan - i Sabāh started to become a force during his era , however , and they assassinated many leading figures in his administration ; according to many sources these victims included Nizām al - Mulk . Governance . The Seljuq power was at its zenith under Malikshāh I , and both the Qarakhanid s and Ghaznavid s had to acknowledge the overlordship of the Seljuqs . The Seljuq dominion was established over the ancient Sasanian domains , in Iran and Iraq , and included Anatolia as well as parts of Central Asia and modern Afghanistan . The Seljuk rule was modelled after the tribal organization common in Turkic and Mongol nomads and resembled a ' family federation ' or ' appanage state ' . Under this organization the leading member of the paramount family assigned family members portions of his domains as autonomous appanage s . Division of empire . When Malikshāh I died in 1092 , the empire split as his brother and four sons quarrelled over the apportioning of the empire among themselves . Malikshāh I was succeeded in Anatolia by Kilij Arslan I , who founded the Sultanate of Rum , and in Syria by his brother Tutush I . In Persia he was succeeded by his son Mahmud I , whose reign was contested by his other three brothers Barkiyaruq in Iraq , Muhammad I in Baghdad , and Ahmad Sanjar in Khorasan . When Tutush I died , his sons Radwan and Duqaq inherited Aleppo and Damascus respectively and contested with each other as well , further dividing Syria amongst emirs antagonistic towards each other . In 1118 , the third son Ahmad Sanjar took over the empire . His nephew , the son of Muhammad I , did not recognize his claim to the throne , and Mahmud II proclaimed himself Sultan and established a capital in Baghdad , until 1131 when he was finally officially deposed by Ahmad Sanjar . Elsewhere in nominal Seljuq territory were the Artuqids in northeastern Syria and northern Mesopotamia ; they controlled Jerusalem until 1098 . The Dānišmand dynasty founded a state in eastern Anatolia and northern Syria and contested land with the Sultanate of Rum , and Kerbogha exercised independence as the atabeg of Mosul . The First Crusade . During the First Crusade , the fractured states of the Seljuqs were generally more concerned with consolidating their own territories and gaining control of their neighbours than with cooperating against the crusaders . The Seljuqs easily defeated the untrained People ' s Crusade arriving in 1096 , but they could not stop the progress of the army of the subsequent Princes ' Crusade , which took important cities such as Nicaea ( İznik ) , Iconium ( Konya ) , Caesarea Mazaca ( Kayseri ) , and Antioch ( Antakya ) on its march to Jerusalem ( Al - Quds ) . In 1099 the crusaders finally captured the Holy Land and set up the first Crusader States . The Seljuqs had already lost Palestine to the Fatimids , who had recaptured it just before its capture by the crusaders . The Second Crusade . During this time conflict with the Crusader States was also intermittent , and after the First Crusade increasingly independent atabegs would frequently ally with the crusader states against other atabegs as they vied with each other for territory . At Mosul , Zengi succeeded Kerbogha as atabeg and successfully began the process of consolidating the atabegs of Syria . In 1144 Zengi captured Edessa , as the County of Edessa had allied itself with the Ortoqids against him . This event triggered the launch of the Second Crusade . Nur ad - Din , one of Zengi ' s sons who succeeded him as atabeg of Aleppo , created an alliance in the region to oppose the Second Crusade , which landed in 1147 . Decline . Ahmad Sanjar had to contend with the revolts of Qarakhanid s in Transoxiana , Ghorid s in Afghanistan and Qarluk s in modern Kyrghyzstan , as well as the nomadic Kara - Khitai s who invaded the East and captured the Eastern Qarakhanid state . The Kara - Khitais then defeated the Western Qarakhanids , a vassal of the Seljuqs at Khujand . The Qarakhanids turned to their overlord the Seljuqs for help , but at the Battle of Qatwan in 1141 , Sanjar was decisively defeated . The Seljuq army suffered great losses and Sanjar barely escaped with his life . The prestige of the Seljuqs became greatly diminished , and they lost all his eastern provinces up to the Syr Darya , with the vassalage of Western Kara - Khanid taken by the Kara - Khitan . Conquest by Khwarezm and the Ayyubids . In 1153 , the Oghuz Turks rebelled and captured Sanjar . He managed to escape three years later but died a year later . Despite several attempts to reunite the Seljuks by his successors , the Crusade s prevented them from regaining their former empire . The atabegs , such as Zengids and Artuqids , were only nominally under the Seljuk Sultan , and generally controlled Syria independently . When Ahmed Sanjar died in 1156 , it fractured the empire even further and rendered the atabegs effectively independent . After the Second Crusade , Nur ad - Din ' s general Shirkuh , who had established himself in Egypt on Fatimid land , was succeeded by Saladin . In time , Saladin rebelled against Nur ad - Din , and , upon his death , Saladin married his widow and captured most of Syria and created the Ayyubid dynasty . On other fronts , the Kingdom of Georgia began to become a regional power and extended its borders at the expense of Great Seljuk . The same was true during the revival of the Armenian Kingdom of Cilicia under Leo II of Armenia in Anatolia . The Abbassid caliph An - Nasir also began to reassert the authority of the caliph and allied himself with the Khwarezmshah Takash . For a brief period , Togrul III was the Sultan of all Seljuq except for Anatolia . In 1194 , however , Togrul was defeated by Takash , the Shah of Khwarezmid Empire , and the Seljuq finally collapsed . Of the former Seljuq Empire , only the Sultanate of Rûm in Anatolia remained . As the dynasty declined in the middle of the thirteenth century , the Mongols invaded Anatolia in the 1260s and divided it into small emirates called the Anatolian beyliks . Eventually one of these , the Ottoman , would rise to power and conquer the rest . Legacy . The Seljuqs were educated in the service of Muslim courts as slaves or mercenaries . The dynasty brought revival , energy , and reunion to the Islamic civilization hitherto dominated by Arabs and Persians . According to the Seljuqs , they brought to the Muslims " fighting spirit and fanatical aggression " . The Seljuqs founded universities and were also patrons of art and literature . Their reign is characterized by Persian astronomers such as Omar Khayyám , and the Persian philosopher al - Ghazali . Under the Seljuqs , New Persian became the language for historical recording , while Arabic language culture shifted from Baghdad to Cairo .