Fall of Tripoli ( 1289 ) The Fall of Tripoli was the capture and destruction of the Crusader state , the County of Tripoli ( in what is modern - day Lebanon ) , by the Muslim Mamluk s . The battle occurred in 1289 and was an important event in the Crusades , as it marked the capture of one of the few remaining major possessions of the Crusaders . Context . The County of Tripoli , though founded as a Crusader State and predominantly Christian , had been a vassal state of the Mongol Empire since around 1260 , when Bohemond VI , under the influence of his father - in - law Hethum I , King of Armenia , preemptively submitted to the rapidly advancing Mongols . Tripoli provided troops in the Mongols ' 1258 sack of Baghdad , as well as the 1260 Mongol invasions of Syria , which caused even further friction with the Muslims . After the Mongols destroyed Baghdad and Damascus , centers of the Abbasid and Ayyubid caliphates , the center of Islamic power shifted to Cairo , with the Egyptian Mamluks . Around the same time , the Mongols were slowed in their westward expansion by internal conflicts in the thinly - spread Empire . The Mamluks took advantage of this to advance northwards from Egypt , and re - establish dominion over Palestine and Syria , pushing the Mongols back to Persia . The Mamluks attempted to take Tripoli in a 1271 siege , but instead were persuaded to agree to a truce , because of the arrival of Prince Edward in Acre that month , with the beginning of the Ninth Crusade . The Mamluks negotiated a truce with Edward as well , though as it turned out his forces had been too small to be very effective . The Mongols , for their part , had not proven to be staunch defenders of their vassal Christian state of Tripoli . Abaqa Khan , the leader of the Mongol Ilkhanate and someone who had been sending envoys to Europe in an attempt to form a Franco - Mongol alliance against the Muslims , had died in 1282 . He was succeeded by Tekuder , a convert to Islam . Under Tekuder ' s leadership , the now Islamic - leaning Mongols were not inclined to defend Christian territories against Muslim advances . This further freed the Mamluks to make attacks against the remaining coastal cities which were still under Crusader control . Tekuder was assassinated in 1284 and replaced by Abaqa ' s son Arghun , who was more sympathetic to Christianity . He continued his father ' s communications with Europe towards the possibility of forming an alliance , but still did not show much interest in protecting Tripoli . Meanwhile , the Mamluks continued to expand their control , conquering Margat in 1285 , and Lattakiah in 1287 . The Muslim Sultan Qalawun still had an official truce with Tripoli , but the Christians themselves gave him an excuse to break it . The Christians had been pursuing an unwise course , as rather than maintaining a united front against the Muslims , they had fallen into bickering battles with each other , of which the best known example was the dispute between the merchant republics , Genoa and Venice . Lucia of Tripoli , ruler of the County of Tripoli , had allied with the Genoese , and was therefore opposed by the Venetians , as well as by Bartolemew Embriaco of Gibelet . Frank envoys from either Bartolemew or the Venetians had been sent to Alexandria , Egypt to ask for the intervention of the Mamluk Sultan Qalawun against the Genoese , on the grounds that the Genoese might potentially dominate the Levant and obstruct or eliminate Mamluk trade if left in power . Because of the Venetian envoys , Qalawun thus had an excuse to break his truce with Tripoli , and he moved north with his army . The siege . Qalawun started the siege of Tripoli in March 1289 , arriving with a sizable army and large catapult s . In response , Tripoli ' s Commune and nobles gave supreme authority to Lucia . In the harbor at the time , there were four Genoese galleys , two Venetian galleys , and a few small boats , some of them Pisan . Reinforcements were sent to Tripoli by the Knights Templar , who sent a force under Geoffrey of Vendac , and the Hospitallers sent a force under Matthew of Clermont . A French regiment was sent from Acre under John of Grailly . King Henry II of Cyprus sent his young brother Amalric with a company of knights and four galleys . Many non - combatants fled to Cyprus . The Mamluks fired their catapults , two towers soon crumbled under the bombardments , and the defenders hastily prepared to flee . The Mamluks overran the crumbling walls , and captured the city on April 26 , marking the end of an uninterrupted Christian rule of 180 years , the longest of any of the major Frankish conquests in the Levant . Lucia managed to flee to Cyprus , with two Marshals of the Orders and Almaric of Cyprus . The commander of the Temple Peter of Moncada was killed , as well as Bartholomew Embriaco . The population of the city was massacred , although many managed to escape by ship . Those who had taken refuge on the nearby island of Saint - Thomas were captured by the Mamluks on April 29 . Women and children were taken as slaves , and 1200 prisoners were sent to Alexandria to work in the Sultan ' s new arsenal . Tripoli was razed to the ground , and Qalawun ordered a new Tripoli to be built on another spot , a few miles inland at the foot of Mount Pilgrim . Soon other nearby cities were also captured , such as Nephin and Le Boutron . Peter of Gibelet kept his lands around Gibelet ( modern Byblos ) for about 10 more years , in exchange for the payment of a tribute to the Sultan . Aftermath . Two years later Acre , the last major Crusade r outpost in the Holy Land was also captured in the Siege of Acre in 1291 . It was considered by many historians to mark the end of the Crusades , though there were still a few other territories being held to the north , in Tortosa and Atlit . However the last of those , the small Templar garrison on the island of Ruad was captured in 1302 or 1303 in a siege . With the Fall of Ruad , was lost the last bit of Crusader - held land in the Levant .