Galleys on which the oarsmen sit two to a bench on the same level dominate Mediterranean naval warfare of the mid-thirteenth century as, for example, the War of Saint Sabas or San Saba, a conflict between the Mediterranean maritime republics of Genoa, aided by the Knights Hospitaller, and Venice, aided by the Knights Templar.

Mediterranean Southwest Europe (1252–1263 CE): Naval Conflict, Architectural Ambition, and Gothic Flourishing

The era 1252–1263 CE in Mediterranean Southwest Europe is marked by significant naval conflicts between maritime republics, ambitious architectural projects across Italy and Iberia, and the flourishing of Gothic style throughout the region.

Naval Warfare: The War of Saint Sabas

Mediterranean naval warfare during this period is dominated by galleys, on which oarsmen sit two to a bench at the same level, enabling greater maneuverability and speed. A prominent example of this naval strategy is the War of Saint Sabas (San Saba), a significant conflict between the maritime republics of Genoa, supported by the Knights Hospitaller, and Venice, allied with the Knights Templar. This conflict underscores the fierce rivalry among Mediterranean naval powers, emphasizing their economic interests, political influence, and control over key maritime trade routes.

Architectural Ambition and Gothic Innovation

The era witnesses the initiation of numerous monumental building projects, exemplifying the era’s cultural ambition and the widespread adoption of the Gothic architectural style:

• In Genoa, construction begins on the Ducal Palace, reflecting the city's growing political and economic prominence.

• Naples commences work on the impressive Cathedral of San Gennaro, showcasing southern Italy’s embrace of Gothic grandeur.

• Florence initiates the ambitious construction of the Santa Maria del Fiore (Florence Cathedral or Duomo), designed by renowned architect Arnolfo di Cambio, epitomizing the Italian Gothic preference for classical harmony and horizontal proportions.

• Florence further expands its Gothic heritage by beginning construction of the Church of Santa Croce, also likely designed by Arnolfo di Cambio, characterized by classical balance and spatial width rather than the vertical emphasis typical of northern European Gothic.

• Additionally, the significant Church of the Badia in Florence exemplifies the ongoing Gothic revival within the city.

• Siena undertakes construction of the Palazzo Pubblico, a secular Gothic building intended to symbolize civic pride and political autonomy.

• In Iberia, construction begins on the Cathedral of Barcelona, demonstrating a distinct fusion of French Gothic style and regional Spanish tastes, notably with a relatively modest clerestory and an imposing nave arcade.

Continued Cultural and Economic Vitality

Despite intense rivalries and warfare, Mediterranean commerce thrives. Genoa, Venice, Barcelona, and Valencia prosper through vibrant trade networks extending across the Mediterranean, facilitating ongoing cultural exchange and economic growth.

Legacy of the Era

The era 1252–1263 CE significantly shapes Mediterranean Southwest Europe through dramatic naval conflicts, ambitious architectural projects, and cultural flourishing expressed through Gothic art and architecture. These developments reflect the region’s dynamic integration of economic prosperity, artistic innovation, and political ambition, leaving a lasting cultural and architectural heritage.

Genoa and Venice, commercial rivals in the eastern Mediterranean, have increasingly made attempts to eliminate each other and to obtain exclusive trading rights at Constantinople and in the Crusaders' Latin colonies.

In 1255, war breaks out between the two Italian city-states.

The series of wars between the two will continue sporadically until 1371.

Many criminals and other undesirables have found their way to Acre.

More important, the earlier homogeneity of a French character has given way to an Italian predominance, but the Italians of Outremer are as divided as they were in Italy.

The Genoese-Venetian rivalry extends to the Levant and occasionally, as at Acre in 1256, results in outright war.

When the Venetians are evicted from Tyre, war grows out of a dispute concerning land in Acre owned by the monastery of Saint Sabas but claimed by both Genoa and Venice.

Genoa has a clear upper hand at first, but its early successes in the War of Saint Sabas are abruptly reversed when the Republic of Pisa, a former ally, signs a ten-year pact of military alliance with Venice.

Venetian admiral Lorenzo Tiepolo breaks through Acre's harbor chain in 1257 and destroys several Genoese ships, conquers the disputed property, and destroys Saint Sabas' fortifications.

Despite throwing up a blockade, he is unable to expel from their quarter of the city the Genoese, who are eight hundred men strong and armed with fifty to sixty ballistae; there are also siege engines among the Venetians.

The famed Genoese crossbowmen are also fighting in Acre: the life of the Count of Jaffa is only spared by a chivalrous Genoese consul who has forbidden his crossbowman to shoot the count from his tower.

Pisa and Venice hire men to row 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 is ten Saracen besants a day and nine a night.

The blockade has lasted more than a year (perhaps twelve or fourteen months), but because the Hospitaller complex is also near the Genoese quarter, food is brought to them quite simply, even from as far away as from Philip of Montfort in Tyre.

The regent of the kingdom, John of Arsuf, who had initially tried to mediate, in August 1257 confirms 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.

Ancona is an ally of Genoa and John seeks by his treaty to bring the feudatories—most of whom are onside—to support Genoa against Venice.

His plan ultimately backfires 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 have the support of the new bailiff, Plaisance of Cyprus, Bohemond VI of Antioch, and the Knights Templar.

At this juncture, Philip of Montfort, who has been providing food to the Genoese in Acre, is one of Genoa's only supporters.

Philip is staying about a mile away from Acre, in a place called "the new Vigny" (la Vignie Neuve) with "eighty men on horses and three hundred archer-villeins from his land".

The barons at Acre, unlike the lords of Armenia and Antioch-Tripoli, remain more disposed to deal with the Muslims, whom they know, than with the terrifying and unknown Mongols.

Philip of Montfort, as per a plan, marches on Acre in June and joins up with a band of Hospitallers while a Genoese fleet attacks the city by sea.

The Genoese navy, numbering some forty-eight galleys and four sailing ships armed with siege engines, under Rosso della Turca is quickly overrun by the Venetians and …

…the Genoese are forced to abandon their quarter and retreat with Philip to Tyre.

The Venetian-Genoese conflict has worn down.

A fragile peace takes effect, though the Genoese are still out of Acre.

Pope Urban IV, who has become understandably worried about the effect of the war in the event of a Mongol attack (a threat that fails to materialize), now organizes a council to reestablish order in the kingdom following five years of fighting.

The period of Latin rule over Constantinopole, from 1204 to 1261, has been the most disastrous in the city's history.

Even the bronze statues have been melted down for coin; everything of value has been taken, including sacred relics, torn from the sanctuaries and dispatched to religious establishments in Western Europe.

Meanwhile, Lascarid supporters in Asia Minor threaten Michael VIII Palaeologus, despite his military successes, with rebellion.

He succeeds, in the eyes of many Greeks, in legitimating his rule, when Nicaean forces under the command of Alexios Strategopoulos, with the aid of the Genoese, the traditional rivals of Venice, are able to recover Constantinople, almost casually.

Whether as the result of Michael's carefully planned ruse or of accident, or both, the great city falls to his general on July 25, 1261, ending the long-shaky Latin Empire and its sadly diminished domain.

Emperor Baldwin II flees the city, and the Venetians are dispossessed of their lucrative commercial center.

Michael, reiterating his claim to the imperial title, has himself crowned sole emperor in the church of Hagia Sophia in August.

On his entrance in Constantinople, Michael abolishes all Latin customs and reinstates most Greek ceremonies and institutions as they had existed before the Fourth Crusade.

He is acutely aware of the danger posed by the possibility that the Latin West, particularly his neighbors in Italy (Charles I of Sicily, Pope Urban VI, and the Venetians) will unite against him and attempt the restoration of Latin rule here.