The Mamluks would achieve a historic victory against the Mongols and halt their advance westwards at the Battle of Ain Jalut.
This made her unpopular, so the young Bohemond VI, through the approval of King Louis IX of France, who was on Crusade at the time, gained permission from Pope Innocent IV to inherit the principality a few months early.
This involved him in a dispute between the Genoese and the Venetians, the War of St. Sabas, which started in 1256 and drew in many of the nobles in the Holy Land, wasted valuable resources and cost tens of thousands of lives.
Bohemond tried to persuade the Genoese to support the Venetians, but the Embriaco family rebelled against him in 1258 and escalated the situation to a civil war which lasted off and on for decades.
The Mongol army had been approaching steadily from central Asia, with Cilician Armenia and Antioch directly in its path.
The Mongols had a deserved reputation of ruthlessness – if settlements in their path did not surrender immediately, the inhabitants were slaughtered by the tens of thousands.
[12][13][14] The Mongols rewarded Bohemond for his allegiance, and returned to him various areas that had been lost to the Muslims, such as Lattakieh, Darkush, Kafr Debbin, and Jabala.
The Mamluks advanced northward from Cairo to engage the Mongols, along the way negotiating an unusual pact of neutrality with the Franks of Acre that allowed the Egyptians to pass through Frankish territory unmolested.
For example, Bohemond and Hethoum controlled the forests of southern Anatolia and Lebanon, the wood of which was needed by the Egyptian Mamluks to build ships.
However, Hulagu was unhappy with Bohemond for replacing the Greek patriarch with a Latin one, as the Byzantine alliance was important to him, against the Turks in Anatolia.
They killed one of Hetoum's sons, took the other prisoner, and laid waste to Cilician Armenia, reducing the capital to ruins.
(...) Warn your walls and your churches that soon our siege machinery will deal with them, your knights that soon our swords will invite themselves in their homes (...) We will see then what use will be your alliance with Abagha"Bohemond begged for a truce, so as not to lose Tripoli as well.
Bohemond died in 1275, leaving a son and three daughters: Bohemond VII, nominal prince of Antioch (though Antioch had ceased to exist) and count of Tripoli; Isabelle, who died young; Lucia, later titular countess of Tripoli; and Marie (d. ca 1280), married to Nicolas de Saint-Omer (d. 1294).