Bohemond I of Antioch in the context of "Tancred, Prince of Galilee"

Alexios I Komnenos (Greek: Ἀλέξιος Κομνηνός, romanized: Aléxios Komnēnós, c. 1057 – 15 August 1118), Latinized as Alexius I Comnenus, was Byzantine emperor from 1081 to 1118. After usurping the throne he was faced with a collapsing empire and constant warfare throughout his reign. Alexios was able to curb the Byzantine decline and begin the military, financial, and territorial recovery known as the Komnenian restoration. His appeals to Western Europe for help against the Seljuk Turks were the catalyst that sparked the First Crusade. Although he was not the first emperor of the Komnenian dynasty, it was during his reign that the Komnenos family came to full power and initiated a hereditary succession to the throne.

The son of John Komnenos and a nephew of Isaac I Komnenos, Alexios served with distinction under three Byzantine emperors. In 1081, he led a rebellion against Emperor Nikephoros III Botaneiates and took the throne for himself. He immediately faced an invasion of the western Balkans by the Normans under Robert Guiscard and his son Bohemond. Despite initial defeats, Alexios secured an alliance with Holy Roman Emperor Henry IV and drove back the Normans, recovering most of Byzantine losses by 1085. In 1091, he achieved a decisive victory over the Pechenegs at the Battle of Levounion in Thrace with the help of Cuman allies.

The Principality of Taranto (Latin: Principatum Tarentinum) was a state in southern Italy created in 1088 for Bohemond I, eldest son of Robert Guiscard, as part of the peace between him and his younger brother Roger Borsa after a dispute over the succession to the Duchy of Apulia.

Taranto became the capital of the principality, which covered almost all of the heel of Apulia. During its subsequent 377 years of history, it was sometimes a powerful and almost independent feudal fief of the Kingdom of Sicily (and later of Naples), sometimes only a title, often given to the heir to the crown or to the husband of a reigning queen. When the House of Anjou was divided, Taranto fell to the house of Durazzo (1394–1463).

The siege of Antioch took place during the First Crusade in 1097 and 1098, on the Crusaders' way to Jerusalem through Syria. Two sieges took place in succession. The Crusader sieged the city held by the Seljuk Empire from 20 October 1097 to 3 June 1098, when the Crusaders successfully took the city. A Seljuk relieving army then sieged the Crusader for three weeks in late June. The second siege led to the Battle of Antioch in which the Crusaders defeated the Seljuks led by Kerbogha. The Crusaders then established the Principality of Antioch, ruled by Bohemond of Taranto.

Antioch (modern Antakya) lay in a strategic location on the Crusaders' route to Judea through the Syrian Coastal mountain range. Supplies, reinforcements and retreat could all be controlled by the city. Anticipating that it would be attacked, the Seljuk governor of the city, Yağısıyan, began stockpiling food and sending requests for help. The Byzantine walls surrounding the city presented a formidable obstacle to its capture, but the leaders of the crusade felt compelled to besiege Antioch anyway.

Cecile of France (1097 – 1145) was a Frankish princess who became countess of Tripoli. She was the daughter of King Philip I of France and Bertrade de Montfort.

Cecile's first marriage was arranged while Prince Bohemond I of Antioch was visiting the French court seeking support against the Byzantine emperor, Alexios I Komnenos. She sailed for Antioch at the end of 1106 and became lady of Tarsus and Mamistra in Cilician Armenia. Cecile married Prince Tancred of Galilee, regent of Antioch, in late 1106.