Siege of Tripoli The Siege of Tripoli lasted from 1102 until July 12 , 1109 and took place on the site of the present day Lebanese city of Tripoli . It took place in the aftermath of the First Crusade and led to the establishment of the fourth crusader state , the County of Tripoli . Background . After the capture of Antioch ( June 1098 ) and the destruction of Ma ' arrat al - Numan ( January 13 , 1099 ) , the Syrian emirs were terrified of the advancing crusade rs and quickly handed over their cities to the Franks . On January 14 , Sultan ibn Munqidh , emir of Shaizar , dispatched an embassy to Raymond IV of Toulouse , one of the leaders of the crusade , to offer provisions and food for men and horses , as well as guides to Jerusalem . In February , the emir of Homs , Janah ad - Dawla , who had fought bravely at the siege of Antioch , offered horses to Raymond . The " qadi " of Tripoli , Jalal al - Mulk , from the Banu Ammar , sent rich gifts and invited the Franks to send an embassy to his city . The ambassadors marvelled at the splendors of the city , and an alliance was concluded . The crusades moved on to Arqa , which they besieged from February 14 to May 13 , before continuing south to Jerusalem ; they did not attack Tripoli or any other possessions of the Banu Ammar . Raymond returns to Tripoli . The Siege of Jerusalem was a success and led to the foundation of the Kingdom of Jerusalem . Most crusaders returned home afterwards ; a second movement set out , encouraged by the success of the First Crusade , but it was mostly annihilated by the Seljuk Turks in Anatolia . Raymond participated in this crusade as well , and returned to Syria after escaping from his defeat at the hands of Kilij Arslan I in Anatolia . He had with him only three hundred men . Fakhr al - Mulk , " qadi " of Tripoli , was not as accommodating to Raymond as his predecessor had been , and called for assistance from Duqaq of Damascus and the governor of Homs . However , the troops from Damascus and Homs defected once they reached Tripoli , and the " qadi " was defeated at the beginning of April , losing seven thousand men . Raymond could not take Tripoli itself , but captured Tortosa , which became the base of all future operations against Tripoli . The siege . The following year , Raymond , with the aid of Byzantine engineers , constructed Mons Peregrinus , " Pilgrim ' s mountain " or " Qalaat Saint - Gilles " ( " fortress of Saint - Gilles " ) , in order to block Tripoli ' s access inland . With the Genoese Hugh Embriaco , Raymond also seized Gibelet . After the Battle of Harran in 1104 , Fakhr al - Mulk asked Sokman , the former Ortoqid governor of Jerusalem , to intervene ; Sokman marched into Syria but was forced to return home . Fakhr al - Mulk then attacked Mons Peregrinus in September , 1104 , killing many of the Franks and burning down one wing of the fortress . Raymond himself was badly wounded , and died five months later in February , 1105 . He was replaced as leader by his nephew William - Jordan , count of Cerdanya . On his deathbed , Raymond had reached an agreement with the " qadi " : if he would stop attacking the fortress , the crusaders would stop impeding Tripolitanian trade and merchandise . The " qadi " accepted . In 1108 , it became more and more difficult to bring food to the besieged by land . Many citizens sought to flee to Homs , Tyre , and Damascus . The nobles of the city , who had betrayed the city to the Franks by showing them how it was being resupplied with food , were executed in the crusader camp . Fakhr al - Mulk , left to wait for help from the Seljuk sultan Mehmed I , went to Baghdad at the end of March with five hundred troops and many gifts . He passed through Damascus , now governed by Toghtegin after the death of Duqaq , and was welcomed with open arms . In Baghdad , the sultan received him with great spectacle , but had no time for Tripoli while there was a succession dispute in Mosul . Fakhr al - Mulk returned to Damascus in August , where he learned Tripoli had been handed over to al - Afdal Shahanshah , vizier of Egypt , by the nobles , who were tired of waiting for him to return . The next year , the Franks gathered in force outside Tripoli , led by Baldwin I of Jerusalem , Baldwin II of Edessa , Tancred , regent of Antioch , William - Jordan , and Raymond IV ' s eldest son Bertrand of Toulouse , who had recently arrived with fresh Genoan , Pisan and Provençal troops . Tripoli waited in vain for reinforcements from Egypt . A compromise decided in the course of a dispute beneath the walls of the city , and arbitrated by Baldwin of Jerusalem , allowed the city to be captured : the County of Tripoli would be divided between the two claimants , William - Jordan , as a vassal of the Principality of Antioch , and Bertrand , as a vassal of Jerusalem . The city fell on July 12 , and was sacked by the crusaders . One hundred thousand volumes of the Dar - em - Ilm library were deemed " impious " and burned . The Egyptian fleet arrived eight hours too late . Most of the inhabitants were enslaved , the others were deprived of their possessions and expelled . Bertrand , Raymond IV ' s illegitimate son , had William - Jordan assassinated in 1110 and claimed two - thirds of the city for himself , with the other third falling to the Genoans . Thus Tripoli became a crusader state ; the rest of the Mediterranean coast had already fallen to the crusaders or would pass to them within the next few years , with the capture of Sidon in 1111 and Tyre in 1124 .