At the same time, he was elected as Captain general of the Sea, as part of the anti-Ottoman crusade being organized by King Ladislaus III of Poland and Hungary and John Hunyadi; however, the Venetians did not engage in any serious activity for the year, and on 11 November Loredan instead was appointed as one of the "savii alle acque" (officials charged with supervising the waterways of the Venetian Lagoon). On 25 April 1444, Loredan was appointed commander of the Venetian and Papal squadrons that would sail to take part in the crusade. His instructions, received on 17 June, were to obstruct the Ottoman Sultan, Murad II, from crossing with his army into Anatolia and moving against the Karamanid ruler Ibrahim, who was allied with the Christian league. In the event, Loredan reached the Turkish Straits too late to stop Murad. As the Christian offensive in the Balkans was delayed, on 9 September he received instructions from Venice to abstain from offensive actions and open secret negotiations with the Sultan, who in the meantime defeated the Karamanids. Once the Crusader army began its invasion, however, he was charged with hindering the Ottoman army from returning to Europe. Loredan blockaded the Dardanelles, but Murad chose to cross the Bosporus north of Constantinople. As a result, on 11 November, at the Battle of Varna, the Ottomans inflicted a crushing defeat on the Crusader army. While Venice negotiated for a peace with the Sultan, Loredan spent the next year cruising with his fleet in the Aegean, in order to protect Venice's possessions and allies from Ottoman reprisals.