The Third Genoese–Venetian War was not a conflict over a single port or a single insult — it was a struggle over trade dominance across the entire Mediterranean basin. Genoese admiral Paganino Doria spent the summer of 1354 conducting raids deep into what Venice regarded as its private sea, striking the Dalmatian islands of Hvar and Korčula and sacking Poreč in Istria. His audacity was deliberate. By raiding the Adriatic, Doria forced the Venetian fleet to abandon its operations near Sardinia and chase him eastward. Doria, meanwhile, collected reinforcements from the Genoese colony at Pera — 10 galleys under Visconte Grimaldi — before beginning the long westward voyage home. He would have to pass by Sapienza. Pisani knew it.

Pisani arrived at the Venetian outpost of Koroni on 11 October, where, by the most widely accepted account, he received instructions from the new Doge of Venice, Marino Faliero, to avoid battle — negotiations to end the war were underway, and the Genoese, with their reinforced fleet, now had superior numbers. Whether those orders existed or whether Pisani simply miscalculated remains disputed. What is certain is that he moved his fleet to Porto Longo and made a fateful decision: he stationed 14 ships at the harbour entrance under Niccolò Querini, then lashed his remaining 21 galleys together at anchor inside the bay. The fleet that could have fought was tied fast to the seafloor. When Doria appeared on 3 November with 35 galleys, the Venetians did not sortie. Doria withdrew — but bad weather kept him from sailing away.

On the morning of 4 November, Doria sent 15 ships under his nephew Giovanni to storm the harbour entrance. The details of how the Venetian blockade at the mouth of Porto Longo failed — whether broken by force or allowed through by confusion or cowardice — are lost to history. What is not lost: Giovanni's ships reached the anchored Venetian fleet, immobilized and unable to maneuver. Pisani surrendered. Querini, now caught between the attacking force inside the harbour and the rest of Doria's fleet outside, had no choice but to follow. More than 4,000 Venetians died. Another 5,400 were taken prisoner. The Genoese suffered, by comparison, almost no losses at all. Paganino Doria returned to Genoa to a triumphal reception and a prize of money equal to the value of his own palace. An annual commemoration was decreed in honor of the victory.

Pisani was transported to Genoa as a prisoner, but was released relatively quickly. Returning to Venice, he faced prosecution. The charges against him were extensive: failing to attack the weaker Genoese fleet at Chios when he had the chance, neglecting to use the fortified harbour at Koroni or Methoni instead of the exposed anchorage at Porto Longo, and various other failures of command. The charges were, in all likelihood, excessive — a city's rage looking for a human form to attach itself to. Pisani was convicted on 5 August, sentenced to imprisonment and a fine of 1,000 pounds, and permanently barred from military command. He died shortly after. The island of Sapienza and the silence of Porto Longo remained.

Sapienza sits a few kilometers off the coast of Methoni, the westernmost cape of the Peloponnese. It is small, scrubby, and largely uninhabited — one of those Mediterranean islands that looks, from the air, like a question mark in the sea. Porto Longo is still a usable anchorage, sheltered from the prevailing westerly winds. On a calm day the water inside the harbour is extraordinarily clear. Nothing marks the site of the battle. The island is now part of a protected nature reserve, home to the Mediterranean monk seal — one of the rarest marine mammals in the world. The ghosts of seven hundred years have settled quietly into the stone and the sea.