Treaty of Nymphaeum, signed on 13 March 1261, obliged Genoa to furnish a fleet of 50 vessels, with their expenses paid by the Emperor, but in exchange secured very advantageous commercial terms; following a successful recovery of Constantinople, the Genoese stood to effectively inherit and even expand upon the privileged position that the Venetians held in the Latin Empire. In the event, Constantinople was recovered by the Nicaean general Alexios Strategopoulos barely a fortnight after the treaty was signed, without the need for Genoese naval assistance. Nevertheless, Michael VIII scrupulously observed the terms of the Treaty of Nymphaeum, as Genoese naval strength was still necessary to confront a potential Venetian counterstrike while a native Byzantine fleet was slowly being re-established. With the Emperor's subsidies, the Genoese were able to increase their fleet strength considerably. For a year after the recapture of Constantinople, both Venice and Genoa remained passive in the Aegean Sea: Venice hesitated to confront the numerically far superior fleet that Genoa had dispatched to the area, and awaited political developments in Italy, while Genoa suffered from internal turmoil with the overthrow of Boccanegra and the assumption of power by a collective leadership representing the noble houses of the city. In the summer of 1262, the Venetians ordered a 37-galley fleet into the Aegean, which met the Genoese fleet of 60 ships under Ottone Vento at Thessalonica. The Genoese refused to engage, but were also able to obstruct Venetian attempts to blockade them in port. A piratical foray by the nobles of Negroponte, who were allied with Venice, into the Marmara Sea was confronted and defeated by a Byzantine–Genoese squadron. Meanwhile, hostilities broke out in the Morea (the Peloponnese peninsula), where Michael VIII dispatched an expeditionary force (in late 1262 or early 1263) against the Principality of Achaea. Despite initial successes, Byzantine attempts to conquer the entirety of the principality were decisively defeated at Prinitza and Makryplagi. Battle Some time in early 1263, a Genoese fleet of 38 galleys and 10 saette, crewed by some 6,000 men and commanded by four admirals, was sailing to the Byzantine fortress and naval base of Monemvasia in the south-eastern Morea. At the island of Settepozzi (Spetses) it encountered a Venetian fleet of 32 galleys, under Guiberto Dandolo, sailing north to Negroponte. The details of the engagement are not very clear. According to the Genoese Annales Ianuenses, when the signal to attack was