[1] After the ten-year peace treaty between Holy Roman Emperor Frederick II and Ayyubid sultan al-Kamil expired in July 1239, a French Crusader army under Theobald I of Navarre was dispatched in response to the call by pope Gregory IX.

[2] On November 2, the Crusader army moved to Ascalon with about 4,000 men, where they were to rebuild the fortress, securing the southern flank of the kingdom against the Egyptians, in anticipation of an attack on Damascus.

The scouts of Peter of Dreux, one of the French commanders, reported a large convoy of herd animals en route to Damascus.

[3] Passing Jaffa on November 12, news reached them that sultan as-Salih Ayyub had sent an army to Gaza to protect the Egyptian border.

They were supported by Hugh of Burgundy, Walter of Jaffa, Balian of Sidon, John of Arsuf and Odo of Montbéliard, and the force totaled 400 to 600 men.

Theobald, Peter of Dreux and the grand masters of the three orders protested expressly against this plan, arguing that the army should march as a whole to Ascalon to confront the enemy.

[4] This part of the army rode through the night, passed Ascalon and reached the river that formed a natural border between the kingdom and the sultanate.

Theobald intended to pursue the enemy army, but refrained from doing so when Armand de Lavoie pointed out that the Muslims would kill their prisoners in the event of an attack.