On 4 February 1463, while serving again as a "savio del consiglio", Loredan was elected as Captain general of the Sea in the conflict with the Ottomans in the Morea. As the Venetians hoped to contain the conflict, his initial orders were marked by caution: he was to patrol the Aegean and defend any Venetian territories, but limit offensive actions to at most capturing Genoese ships. Following the Ottoman capture of Argos on 3 April, however, the situation changed, and Venice declared war on the Ottomans. Between June and August, Loredan landed an army under the Marquis Bertoldo d'Este off Modon and Nauplia. The campaign initially made rapid gains: Argos was recaptured in early August, and the Venetians refortified the Isthmus of Corinth, restoring the Hexamilion wall and equipping it with many cannons. They then proceeded to besiege the fortress of the Acrocorinth, which controlled the northwestern Morea. The Venetians engaged in repeated clashes with the defenders and with the relief army under Turahanoğlu Ömer Bey, until they suffered a major defeat on 20 October, which resulted in the wounding and subsequent death of d'Este. The Venetians were then forced to lift the siege and retreat to the Hexamilion. Following the arrival of substantial Ottoman reinforcements under the Grand Vizier Mahmud Pasha Angelović the Venetians, whose army had been depleted by dysentery, abandoned the Hexamilion without a fight and retreated to their coastal fortresses. The Ottomans razed the wall yet again and advanced into the Morea. Argos surrendered and was razed, and several forts and localities that had recognized Venetian authority reverted to their Ottoman allegiance.