The war grew out of a dispute concerning land in Acre then owned by Mar Saba (the monastery of Saint Sabbas) but claimed by both Genoa and Venice.

Initially the Genoese navy had a clear upper hand, but its early successes were abruptly reversed when the Republic of Pisa, a former ally, signed a ten-year pact of military alliance with Venice.

[6] At that point, in August 1257, the regent of the kingdom, John of Arsuf, who had initially tried to mediate, confirmed 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.

Philip was staying about a mile away from Acre, in a place called the New Vineyard (la Vigne Neuve) with "80 men on horses and 300 archer-villeins from his land" (lxxx.

Pope Urban IV, who had become understandably worried about the effect of the war in the event of a Mongol attack, a threat that passed without materialising, now organised a council to re-establish order in the kingdom following five years of fighting.

[12] On 16 August 1267, Genoa managed to capture the Tower of Flies and blockade the harbour of Acre for twelve days before being evicted by a Venetian flotilla.