The Principality of Antioch, a crusader state ruled since 1233 by Bohemond V, who is simultaneously Count of Tripoli, had played no important role in the Fifth Crusade, Holy Roman Emperor Frederick II's struggles to take back Jerusalem in the Sixth Crusade, or in the Seventh Crusade, currently being waged by Louis IX of France.

The son of Bohemond IV and Plaisance of Gibelet, the prince, like his father before him, has a notorious dislike for the Knights Hospitaller and the neighboring Kingdom of Armenia, preferring an alliance with the Knights Templar.

Peace with Armenia is assured only shortly before his death in January 1252, with the mediation of King Louis.

Bohemond’s son and successor, being only fifteen, succeeds under the regency of the Dowager Princess, Luciana (Lucienne) di Caccamo-Segni, a great-niece of Pope Innocent III.

However, Luciana never leaves Tripoli, instead handing over the government of the principality to her Roman relatives.

This makes her unpopular, so the young Bohemond VI gains the approval of King Louis, who is on Crusade at this time, to get permission from Pope Innocent IV to come of age a few months early.

Bohemond VI marries Sibylla, an Armenian princess, in 1254, ending the power struggle between the two states, although by this point Armenia is the more powerful of the two and Antioch is essentially a vassal state.

Both, however, are soon to be swept up by the conflict between the Mamluks and the Mongols.

Many criminals and other undesirables have found their way to Acre.

More important, the earlier homogeneity of a French character has given way to an Italian predominance, but the Italians of Outremer are as divided as they were in Italy.

The Genoese-Venetian rivalry extends to the Levant and occasionally, as at Acre in 1256, results in outright war.

When the Venetians are evicted from Tyre, war grows out of a dispute concerning land in Acre owned by the monastery of Saint Sabas but claimed by both Genoa and Venice.

Genoa has a clear upper hand at first, but its early successes in the War of Saint Sabas are abruptly reversed when the Republic of Pisa, a former ally, signs a ten-year pact of military alliance with Venice.

Hulagu has probably always intended to take Baghdad, which the Mongols have been meaning to attack for over ten years, but he uses the caliph's refusal to send troops to him as a pretext for conquest, since his brother the Great Khan has ordered him to be merciful to those who submit.

The Mongol army sets out for Baghdad in November of 1257, led by Hulagu and the Han Chinese commander Guo Kan in vice-command.

The latter had participated in the final drive in the conquest of the Jin Dynasty, including the capture of Kaifeng, and may have served in the European campaign with Subutai a few years following the fall of the Jin Dynasty.

By order of Mongke Khan, one in ten fighting men in the entire empire have been gathered for Hulagu's army, probably the largest ever fielded by the Mongols.

The attacking army also has a large contingent of Christian forces levied from tributary states.

By the time that the Mongols reach Baghdad, their army includes even some Frankish forces from the Principality of Antioch, whose prince, Bohemond VI, had on the advice of his father-in, law, Hethum of Little Armenia, submitted to Mongol overlordship.

The main Christian force seems to have been the Georgians, who are to take a very active role in the destruction to follow.

Also, Ata al-Mulk Juvayni describes Cicilian Armenians, Persians, and Turks as participants in the siege, together with about one thousand Chinese artillery experts.

Rocket technology had first become known to Europeans following their use by the Mongols Genghis Khan and Ögedei Khan when they conquered parts of Russia, Eastern, and Central Europe.

The Mongolians had acquired the Chinese technology by conquest of the northern part of China and also by the subsequent employment of Chinese rocketry experts as mercenaries for the Mongol military.

Reports of the Battle of Sejo in the year 1241 describe the use of rocket-like weapons by the Mongols against the Magyars.

They appear in literature describing the capture of Baghdad in 1258 by the Mongols.

Venetian admiral Lorenzo Tiepolo breaks through Acre's harbor chain in 1257 and destroys several Genoese ships, conquers the disputed property, and destroys Saint Sabas' fortifications.

Despite throwing up a blockade, he is unable to expel from their quarter of the city the Genoese, who are eight hundred men strong and armed with fifty to sixty ballistae; there are also siege engines among the Venetians.

The famed Genoese crossbowmen are also fighting in Acre: the life of the Count of Jaffa is only spared by a chivalrous Genoese consul who has forbidden his crossbowman to shoot the count from his tower.

Pisa and Venice hire men to row their galleys in Acre itself during the siege: the average rate of pay of a Pisan- or Venetian-employed sailor on one of their galleys is ten Saracen besants a day and nine a night.

The blockade has lasted more than a year (perhaps twelve or fourteen months), but because the Hospitaller complex is also near the Genoese quarter, food is brought to them quite simply, even from as far away as from Philip of Montfort in Tyre.

The regent of the kingdom, John of Arsuf, who had initially tried to mediate, in August 1257 confirms a treaty with the city of Ancona, granting it commercial rights in Acre in return for aid of fifty men-at-arms for two years.

Ancona is an ally of Genoa and John seeks by his treaty to bring the feudatories—most of whom are onside—to support Genoa against Venice.

His plan ultimately backfires and John of Jaffa and John II of Beirut "manipulated the complex regency laws" in order to bring the feudatories of the Kingdom of Jerusalem into a position of support for Venice.

In this they have the support of the new bailiff, Plaisance of Cyprus, Bohemond VI of Antioch, and the Knights Templar.

At this juncture, Philip of Montfort, who has been providing food to the Genoese in Acre, is one of Genoa's only supporters.

Philip is staying about a mile away from Acre, in a place called "the new Vigny" (la Vignie Neuve) with "eighty men on horses and three hundred archer-villeins from his land".

Hethum continues as a vassal of the Mongols; his son-in-law, …

…Bohemond VI of Antioch-Tripoli, a principality increasingly aloof and through intermarriage closely tied to Armenia, follows suit.

The barons at Acre, unlike the lords of Armenia and Antioch-Tripoli, remain more disposed to deal with the Muslims, whom they know, than with the terrifying and unknown Mongols.

Philip of Montfort, as per a plan, marches on Acre in June and joins up with a band of Hospitallers while a Genoese fleet attacks the city by sea.

The Genoese navy, numbering some forty-eight galleys and four sailing ships armed with siege engines, under Rosso della Turca is quickly overrun by the Venetians and …

…the Genoese are forced to abandon their quarter and retreat with Philip to Tyre.

Baibars, a Kipchak Turk captured by the Mongols and sold as a slave in the Kipchak steppe, had ended up in Syria, where his first master, the emir (prince) of Hama, had been suspicious of Baibars because of his unusual appearance (he was dark-skinned, very tall and having a cataract in one of his bluish eyes).

Baibars had been quickly sold to a Mamluk officer and sent to Egypt, where he had become a bodyguard to the Ayyubid ruler As-Salih Ayyub.

At the age of about twenty-seven, he was a commander of the Mamluks in around 1250, when he had defeated the Seventh Crusade of Louis IX of France.

He is still a commander under Sultan Qutuz in 1259, by which time the Mongol Khanate of Persia, the Il-Khanate, claims dominion over the Seljuq Sultanates, the Kingdoms of Armenia and Georgia, and the Empire of Trebizond.

The Mongol forces combine with those of their Christian vassals in the region, such as the army of Cilician Armenia under Hetoum, and the Antiochene Franks of Bohemond.

This force now sets out to conquer Muslim Syria, domain of the weakened Ayyubid dynasty.

As the Mongols march toward Aleppo, some of an-Nasir Yusuf's advisors recommend surrendering to Hulagu as the best solution.

This angers Baibars and his Mamluks, who attempt to assassinate an-Nasir Yusuf, but he escapes and flees with his brother to the castle of Damascus, also sending his wife, son, and money to Egypt.

The Mongols arrive at Aleppo in December 1259.

Turanshah, the uncle of an-Nasir Yusuf, refuses to surrender.

After a siege of seven days, the Mongols storm Aleppo and massacre its population for another five days.

Turanshah leaves the city and dies a few days later.