The Principality of Antioch (Latin: Principatus Antiochenus; Norman: Princeté de Antioch) was one of the Crusader states created during the First Crusade which included parts of Anatolia (modern-day Turkey) and Syria. The principality was much smaller than the County of Edessa or the Kingdom of Jerusalem. It extended around the northeastern edge of the Mediterranean, bordering the County of Tripoli to the south, Edessa to the east, and the Byzantine Empire or the Kingdom of Armenia to the northwest, depending on the date.
It had roughly 20,000 inhabitants in the 12th century, most of whom were Armenians and Greek Orthodox Christians, with a few Muslims outside the Antioch city itself. Most of the crusaders who settled there were of Norman origin, notably from the Duchy of Apulia and Calabria in southern Italy, as were the first rulers of the principality, who surrounded themselves with loyal subjects. Few of the inhabitants apart from the crusaders were Roman Catholic even though the city was under the jurisdiction of the Latin Patriarchate of Antioch, established in 1100. This patriarchate would endure as a titular one after the Crusades, until it was dropped in 1964.
The city of Antioch had been a major Byzantine stronghold in the area under the control of a dux before falling to the Seljuk Turks in 1084. Therefore, it was one of the cities the army of the First Crusade aimed to capture on its way to Jerusalem. While Baldwin of Boulogne headed east from Asia Minor to set up the County of Edessa, the main army of the First Crusade continued south to besiege Antioch in late October 1097. The army consisted of various leaders who had sworn to return all territory that had belonged to the Byzantine Empire as well as a Byzantine contingent under the command of the general Tatikios. With over four hundred towers, the city's defenses were formidable. The siege lasted throughout the winter, with much attrition among the Crusader force, who were often forced to eat their horses, or, as legend has it, the bodies of fellow Christians who had not survived. There were several attempts by neighbouring Turkish chiefs to relieve the town, but these were beaten back such as during the Battle of the Lake of Antioch under the military leadership of Bohemond of Taranto.
In May 1098 another relief force under Kerbogha, atabeg of Mosul, approached the city and thus it became important for the crusaders to act fast. Bohemond convinced a guard in one of the towers, an Armenian and former Christian named Firouz, to let the Crusaders enter the city on 2 June 1098. Only four days later, a Muslim army from Mosul, led by Kerbogha, arrived to besiege the Crusaders. Alexios I Komnenos, the Byzantine emperor, was on his way to assist the Crusaders, but upon hearing rumours that the city had fallen to the Muslims, Alexios turned back.
The Crusaders withstood the siege, with help from a mystic named Peter Bartholomew. Peter claimed he had been visited by Andrew the Apostle, who told him that the Holy Lance that pierced Christ's side as he was on the cross was located in the city. Excavations took place in the Basilica of Saint Peter and the Lance was discovered by Peter himself. Although it is possible Peter planted it there himself (the papal legate Adhemar of Le Puy believed this to be the case), it raised the spirits of the Crusaders as well as of the local Armenians and Greeks. With the relic at the head of the army, Bohemond marched out to meet the besieging Muslim force, which was defeated in the battle of Antioch in 1098. According to the Crusaders, an army of saints appeared to help them on the battlefield.
After this victory a lengthy dispute over who should control the city followed. Bohemond stated that the oath sworn to Alexios was nullified by Alexios' failure to bring them aid. He was resisted by count Raymond of Toulouse, who maintained that the city should be returned to Alexios and who would later found the County of Tripoli. Bohemond and his Italian Norman followers eventually won, not least because of the death of Adhemar of Le Puy, who had been the spiritual leader of the crusade and had been determined to cooperate with the Byzantines. Bohemond was already Prince (allodial lord) of Taranto in Italy. He desired to continue such independence in his new lordship, so he did not attempt to receive the title of Duke from the Byzantine Emperor, nor any other title with deep feudal obligations.
Bohemond started immediately after the victory against Kerbogha to secure and expand his principality. In August 1098 he crossed the Amanus Mountains to Cilicia to take control of the towns his nephew Tancred had captured in the previous summer. After the main crusade army left for Jerusalem in 1099, he took full control of Antioch as well as of the surrounding places such as Artah and the harbour of St. Symeon. Bohemond then attempted to take the harbour town of Latakia which was under Byzantine possession, but he had to leave after Raymond and the other crusading lords, who had in the meantime conquered Jerusalem, forced him to. In December 1099 Bohemond travelled to Jerusalem and had three priests consecrated as bishops for his principality.
Following Bohemond's capture in battle with the Danishmends in 1100, his nephew Tancred became regent. Tancred expanded the borders of the Principality, seizing the cities of Tarsus and Latakia from the Byzantine Empire. However those newly captured cities along with other territory were lost after the Battle of Harran when Baldwin II of Edessa was captured. Bohemond was released in 1103 and went to Italy to raise more troops in 1104, during which time Tancred remained regent of Antioch. Bohemond used the troops he raised to attack the Byzantines in 1107. Bohemond was defeated at Dyrrhachium in 1108 and was forced by Alexius I to sign the Treaty of Devol, making Antioch a vassal state of the Byzantine Empire upon Bohemond's death. Bohemond had promised to return any land that was seized from the Muslims when the Crusaders passed through Constantinople in 1097. Bohemond also fought at Aleppo with Baldwin and Joscelin of the County of Edessa; when Baldwin and Joscelin were captured, Tancred became regent in Edessa as well. Bohemond left Tancred as regent once more and returned to Italy, where he died in 1111.
Alexius wanted Tancred to return the Principality in its entirety to Byzantium, but Tancred was supported by the County of Tripoli and the Kingdom of Jerusalem. Tancred, in fact, had been the only Crusade leader who did not swear to return conquered land to Alexius (though none of the other leaders, save for Raymond IV of Toulouse, kept their oaths anyway). Tancred died in 1112 and was succeeded by Bohemond II, under the regency of Tancred's nephew Roger of Salerno, who defeated a Seljuk attack in 1113.
On June 27, 1119, Roger was killed at the Ager Sanguinis (the Field of Blood), and Antioch became a vassal state of Jerusalem with King Baldwin II as regent until 1126 (although Baldwin spent much of this time in captivity in Aleppo). Bohemond II, who married Baldwin's daughter Alice, ruled for only four years, and the Principality was inherited by his young daughter Constance; Baldwin II acted as regent again until his death in 1131, when Fulk of Jerusalem took power. In 1136, Constance, still only 8 years old, married Raymond of Poitiers, who was 36.
Raymond, like his predecessors, attacked the Byzantine province of Cilicia. This time, however, Emperor John II Komnenos fought back. He arrived in Antioch in 1138 and forced Raymond to swear fealty to him. There then followed a joint campaign as John led the armies of Byzantium, Antioch and Edessa against Muslim Syria. Aleppo proved too strong to attack, but the fortresses of Balat, Biza'a, Athereb, Maarat al-Numan and Kafartab were taken by assault. Although John fought hard for the Christian cause in the campaign in Syria, his allies, Prince Raymond of Poitiers and Count Joscelin II of Edessa, sat around playing dice instead of helping John to press the Siege of Shaizar. The city was taken, but the citadel defied assault. The Emir of Shaizar offered to pay a large indemnity, become John's vassal, and pay yearly tribute; the offer was reluctantly accepted by the emperor. On the return of the army to Antioch, a riot instigated by Joscelin II of Edessa forced the emperor to leave without the citadel being surrendered to him. John had plans to reconquer Antioch and become an effective overlord of the remaining Crusader states, but he died in 1143.