War of Saint Sabas The War of Saint Sabas or San Saba ( 1256 – 1270 ) was a conflict between the Mediterranean maritime republics of Genoa ( aided by Philip of Monfort , John of Arsuf , and the Knights Hospitaller ) and Venice ( aided by the Count of Jaffa and the Knights Templar ) . Background . The war began when the Venetians were evicted from Tyre in 1256 and war grew out of a dispute concerning land in Acre then owned by the monastery of Saint Sabas but claimed by both Genoa and Venice . Initially Genoa 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 . In 1257 a Venetian admiral , Lorenzo Tiepolo , broke through Acre ' s harbour chain and destroyed several Genoese ships , conquered the disputed property , and destroyed Saint Sabas ' fortifications ; however he was unable to expel the Genoese , who were 800 men strong and armed with 50 – 60 ballistae , from their quarter of the city despite throwing up a blockade ; there were also siege engines among the Venetians . The famed Genoese crossbowmen were also fighting in Acre : the life of the count of Jaffa was only spared by a chivalrous Genoese consul who forbade his crossbowman to shoot the count from his tower . Pisa and Venice were hiring men to man 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 was ten Saracen besants a day and nine a night . The blockade lasted more than a year ( perhaps twelve or fourteen months ) , but because the Hospitaller complex was also near the Genoese quarter , food was brought to them quite simply , even from as far away as Philip of Montfort in Tyre . 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 . Though Ancona was an ally of Genoa and John sought by his treaty to bring the feudatories — most of whom were onside — to support Genoa against Venice , his plan ultimately backfired 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 had the support of the new bailiff , Plaisance of Cyprus , Bohemond VI of Antioch , and the Knights Templar . At this juncture , Philip of Montfort , who had been providing food to the Genoese in Acre , was one of Genoa ' s only supporters . Philip was staying about a mile away from Acre , in a place called " the new Vigny " ( " la Vignie Neuve " ) with " 80 men on horses and 300 archer - villeins from his land " ( " lxxx . homes a chevau et . ccc . archers vilains de sa terre " ) . In June , as per a plan , he marched on Acre and joined up with a band of Hospitallers while a Genoese fleet attacked the city by sea . The Genoese navy , numbering some 48 galleys and four sailing ships armed with siege engines , under Rosso della Turca was quickly overrun by the Venetians and the Genoese had to abandon their quarter and retreat with Philip to Tyre . The conflict wore down and by 1261 a fragile peace was in effect , though the Genoese were still out of Acre . 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 . The Genoese then approached Michael VIII Palaiologos , Emperor of Nicaea . After the Treaty of Nymphaeum was ratified in 1261 , the emperor funded fifty ships to fight the Venetians . After this assault , in 1264 , the Venetians returned to Tyre to conquer it , but backed out when Tyre received reinforcements . During the continuous skirmishing of the 1260s , both sides employed Muslim soldiers , mostly Turcopoles , against their Christian foes . In 1266 , the Genoese had made an alliance with Baybars , who was to outfit some troops for an expedition against Acre , but the Genoese ' promised fleet never got underway . In 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 . The ongoing warfare between Genoa and Venice had a major negative impact on the Kingdom ' s ability to withstand external threats to its existence . Save for the religious buildings , most of the fortified and defended edifices in Acre had been destroyed at one point or other ( and Acre looked as if it had been ravaged by a Muslim army ) and according to Rothelin , the continuator of William of Tyre ' s " History " , 20 , 000 men in total had lost their lives , a frightful number considering the Crusader states were chronically short on soldiery . The War of Saint Sabas was settled in 1270 with a pact to cease the hostilities between the Venetians and the Genoese . In 1288 , Genoa finally received their quarter in Acre back .