Brief History of the Wars Between Venice, Genoa and Pisa

1. Clearing the Western Mediterranean of Muslims

Initially, Genoa and Pisa were allies. They collaborated in freeing Sardinia and Corsica from Saracen control. The pope, to reward them, granted them joint control over these islands. They were to be the vanguard of protection against further Muslim attacks. But it also meant that there was now a lot of trade and money at stake.

2. Genoa vs Pisa

Sharing trade in the same area bred competition. Competition bred rivalry. Rivalry bred enmity. And enmity bred war.

Pisa struck the first blow. In 1241, at the Battle of Giglio, using as a casus belli the fact of a conflict between Holy Roman Emperor and the Pope, they allied with the Sicilians and decisively defeated the Genoese fleet.

Genoa was down, but not out. Florence was also growing and looking to acquire a sea port. Pisa, then, had to worry about two simultaneous enemies. The pressure proved to be insurmountable. In 1284, at the Battle of Meloria, Pisa was defeated by Genoa, its fleet nearly annihilated.

After this, Pisa became easy pickings. Porto Pisano fell to the Genoese a few years after the battle of Meloria. And a weakened Pisa would in time fall to a rising Florence.

3. Genoa vs. Venice

As an unforeseen aftereffect of the Crusades, there was a lot of money that came from transporting crusading armies to the Levant, supplying the crusader kingdoms, purchasing goods there, and selling those goods back in Europe. Competition for that trade led to conflict between Genoa and Venice.

Unfortunately for Genoa, their conflict with Venice started long before they had defeated the Pisans. Venice defeated Genoa in the War of St. Sabas, 1256-1270, with the help of the Pisans. The war was not enough to permanently cripple Genoa, however, and they plotted their revenge by engineering the overthrow of the Latin emperors of Constantinople and their replacement with a returned Greek dynasty that rewarded them with the trading contracts which the Venetians had previously enjoyed. Flushed with the money from this venture Genoa rebuilt its fleet and severely defeated Venice in 1298 at the battle of Curzola.

But structurally speaking Venice was still in a better position.

The main problem faced by Genoa was internal division. Whereas in Venice the aristocrats were definitely in charge and could impose their will on foreign policy, in Genoa there was constant division over how much to sacrifice and how vigorously to prosecute the war against Venice. And in terms of resource mobilization, Venice had a clear edge.

After many more conflicts, the Venetians finally won at Chioggia in 1380. They would have supreme control over trade in the Mediterranean until the Turks arrived.