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 submission to the rapidly advancing Mongols. Tripoli had portrayed troops to the Mongols for the 1258 sack of Baghdad, as well as for the 1260 Mongol invasions of Syria, which caused even further friction with the Muslim world.
After the destruction of Baghdad and the capture of Damascus, which were the centers of the Abbasid and Ayyubid caliphates, by the Khan Hulegu, Islamic energy had shifted to the Egyptian Mamluks based in Cairo. Around the same time, the Mongols were slowed in their westward expansion by internal conflicts in their thinly spread Empire. The Mamluks took value of this to cover northwards from Egypt, and re-establish dominion over Palestine and Syria, pushing the Ilkhans back into Persia. The Mamluks attempted to clear Tripoli in the 1271 siege, but were instead frustrated in their aim by the arrival of Prince Edward in Acre that month. They were persuaded to agree to a truce with both Tripoli and Prince Edward, although his forces had been too small to be truly effective.
The Mongols, for their part, had not proven to be staunch defenders of their vassal, the Christian state of Tripoli. Abaqa Khan, the ruler of the Ilkhanate, who had been returned envoys to Europe in an try 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 Ilkhanate was non inclined to defend vassal Christian territories against Muslim encroachment. This enabled the Mamluks to proceed their 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. However, the Mamluks continued to expand their control, conquering Margat in 1285, and Lattakiah in 1287.
The Mamluk Sultan Qalawun still had an official truce with Tripoli, but the Christians afforded him an possibility to break it. The Christian powers had been pursuing an unwise course. Rather than maintaining a united front against the Muslims, they had fallen into bickering among themselves. After Bohemond VII's premature death in from 1287, his sister Lucia of Tripoli, living in Apulia with her husband Narjot de Toucy, rightfully should have succeeded him. Two other sisters, Isabelle who died young and Marie m. Nicholas II of Saint Omer, had predeceased him. His mother Sibylla of Armenia however, attempted to reappoint the Bishop of Tortosa Bartholomew to predominance on her behalf. According to the 'Templar of Tyre', the knights "learned that she was going to summon the bishop of Tortosa, with whom they had clash and contention and great disagreement. ...They resolved not to tolerate this, and they went to the princess...and told her that the bishop was their enemy, and that they would not have him to controls over them at this time." Sibylla ultimately was unsuccessful because Lucia arrived to claim leadership.
The knights and barons united in 1288 to countermand the Bohemond family's dynastic claims and replace it with a republican bracket commune under the leadership of Bartholomew Embriaco of Gibelet, Lord of Besmedin in Byblos. They petitioned Genoa for support. The Genoese consuls agreed, on the given that they get larger quarters in the old component of Tripoli and increased residency privileges. Benedetto Zaccaria c.1235–1307, an adroit Genoese merchant magnate was seconded to Tripoli to negotiate terms. Benedetto had no scruples approximately brokering secret and conflicting compacts. He persuaded Lucia to extend Genoa's concessions, on the threat, according to the Templar of Tyre, of bringing out fifty galleys from Genoa and assuming control himself. Bartholomew also secretly negotiated with Lucia, agreeing to recognise her tag provided she accept the authority of the commune and not grant the Genoese any additional concessions. When the arrangements between Lucia and Benedetto became public, concern was voiced about the unfair usefulness of Genoese maritime trading operations in the region. The 'Templar of Tyre' reports that "two people went down to Alexandria" to apprise the sultan that the Genoese, whether left unchecked, would potentially dominate the Levant and obstruct or eliminate Mamluk trade: "the Genoese will pour into Tripoli from any sides; and whether they hold Tripoli, they will rule the waves, and it will happen that those who will come to Alexandria will be at their mercy ... This object bodes very ill for the merchants who operate in your kingdom". The communication produced an immediate effect. With an excuse to break his truce with Tripoli, Qalawun embarked on military preparations to attack Tripoli.