Berke Berke Khan ( died 1266 ) ( also Birkai ; , ) was the ruler of the Ulus of Jochi or Kipchak Khanate who effectively consolidated the power of the Blue Horde and White Horde s from 1257 to 1266 . He succeeded his brother Batu Khan of the Blue Horde ( West ) and was responsible for the first official establishment of Islam in a khanate of the Mongol Empire . He allied with the Egyptian Mamluk s against another Mongol khanate based in Persia , the Ilkhanate . Name . Berke is a name used by both Turkic peoples and Mongols . In the Mongolian language " Berkh " literally means " strong " . " Berk " also has many meanings like " solid " , " powerful " , and " in power " in the Old Turkic language . Background . Berke was one of the sons of Jochi , the eldest son of Genghis Khan . Berke was present , with several of his brothers , at the inauguration of his uncle Ögedei as Great Khan in 1229 . In 1236 , Berke joined his brothers Orda , Sinkur , and Siban and an assortment of cousins under the leadership of Batu Khan . The vast army , comprising some 150 , 000 soldiers , marched from Siberia and into the territory of the Muslim Volga Bulgars and Kipchaks , whom they subdued . Batu and Subutai sent Berke to the country north of the Caucasus to conquer the Kipchaks there . Next they devastated the principalities of Ryazan and Suzdal in 1237 , and marched further into Russia . During the winter of 1238 - 39 , Berke defeated the Kipchaks and imprisoned the chief of the Merkit s . He afterwards subdued the steppe watered by the Kuma and the Terek . Berke further served under his brother during the invasion of Europe , fighting at the Battle of the Mohi , where the Hungarian army was decimated . When Ögedei Khan died , and all the princes of the blood were summoned to return to Mongolia to select a Great Khan , Berke and his brothers joined Batu in his bid for power . When that failed , the Kipchak Khanate settled on the territories , which are now parts of Russia and Kazakhstan , and looked east to defend themselves against their cousins . Conversion to Islam . Berke Khan adopted Islam in the city of Bukhara . When he was at Saray - Jük , Berke met a caravan from Bukhara and questioned them about their faith . Berke was convinced of the truth from the caravan travellers and became a Muslim . Berke then persuaded his brother Tukh - timur to convert to Islam as well . In 1248 Batu sent Berke , along with his brother Tukh - timur , to Mongolia in order to install Möngke Khan on the throne of Great Khan . When he arrived , he invited the Chagatai and Ogedeyd families several times . That is why , Berke conducted the kurultai in 1251 and had Möngke enthroned . Berke organized everything under strict conditions . Assuming the Kipchak Khanate . When Batu died in 1255 , he was briefly succeeded by his son Sartak , before Berke assumed leadership in 1257 . He was an able ruler and succeeded in maintaining and stabilizing the Golden Horde , western khanate of Mongol Empire . During his government , the Mongols finally defeated the rebellion of Danylo of Halych and made a second attack against Poland and Lithuania , led by general Burundai ( Lublin , Zawichost , Sandomierz , Kraków and Bytom were plundered ) in 1259 . Also in 1265 there was a raid against Bulgaria and Byzantine Thrace . Michael of Byzantine Empire also sent much valuable fabric to the Golden Horde as a tribute thereafter . Berke - Hulagu War . Berke soon became a devout Muslim . His conversion resulted in the Blue Horde becoming primarily Muslim , although there were still animists and Buddhists among them . Berke had a deadly determination to deal with Hulagu Khan , who had murdered the Caliph Al - Musta ' sim , and whose territorial ambitions in Syria and Egypt threatened Berke ' s fellow Muslims . In the meantime , the Mongols led by Kitbuqa had fallen out with the crusaders holding the coast of Palestine , and the Mamluks were secured a pact of neutrality with them , pass through their territory , and destroy the Mongol army at the Battle of Ain Jalut . Kitbuqa was killed . Palestine and Syria were permanently lost , the border remaining the Tigris for the duration of Hulagu ' s dynasty . Berke ' s vow of vengeance against Hulagu had to wait until the latter ' s return to his lands after the death of Möngke Khan . Hulagu returned to his lands by 1262 , but instead of being able to avenge his defeats , was drawn into civil war with Berke and the Blue Horde . Berke Khan had promised such a defeat in his rage after Hulagu ' s sack of Bagdad ; Berke was a Muslim . Muslim historian Rashid - al - Din Hamadani quoted Berke Khan told his Mongols and Muslim subjects , protesting the attack on Baghdad : Before his succession , He also complained Batu " We helped Möngke to enthrone . But he forgot who the enemy is or friend is . Now , he is starving the lands of our friend Caliph . It is abject " . It is notable that Berke Khan kept his promise , allying himself with the Mamluks , ( Berke sought an alliance with the Mamluk sultan Baibars against Hulagu ) and when Hulagu returned to his lands in 1262 , after the succession was finally settled with Kublai as the last Great Khan , and massed his armies to avenge Ain Jalut and attack the Mamluks , Berke Khan initiated a series of raids in force which drew Hulagu north to meet him . This was the first open conflict between Mongols , and signaled the end of the unified empire . But the reason of the conflict between Berke and Hulagu was not only religion . It was territory . Möngke khan gave Azerbaijan , which was given to Jochi by Chinghis khan before , to his brother Hulagu . Although , Berke did not like the situation , he was patient till Möngke ' s death . Finally , in 1262 the conflict turned into open war . Hulagu Khan suffered severe defeat in an attempted invasion north of the Caucasus in 1263 . Hulagu ' s forces were crushed at the Terek river by Berke ' s nephew Nogai , forcing Hulagu into retreat ; he died in 1265 . Also Chagatai khan Alghu invaded Khwarizm and annexed Golden Horde lands . Jochid army tried to halt his advance unsuccessfully . Berke also supported Great Khan claimant Ariq Böke , and he minted coins in the name of Ariq Böke . Yet , Kublai defeated Ariq Böke by 1264 . Kublai called both Hulagu and Berke to discuss about Ariq Böke ' s matter . However , both of them noted that they could not come to the Kurultai at the moment , and the new Kurultai was never held . Aftermath . As Berke sought to cross the Kura river to attack Hulagu ' s son , Abaqa Khan , he fell ill and died sometime between 1266 and 1267 . He was succeeded by his grandnephew , Mengu - Timur . The policy of alliance with the Mamluks , and containment of the Ilkhanate , was continued by Mengu - Timur . Many historians are in agreement that the intervention by Berke against Hulagu saved the remainder of the " Holy Land " , including Mecca and Jerusalem , from the same fate as Baghdad .