On 8 April 1481, Pope Sixtus IV issued the papal bull Cogimur iubente altissimo, which called for a crusade against the Ottomans, who had occupied Otranto, in southern Italy.
Portugal decided to send a squadron into Otranto under command of the bishop of Évora, Garcia de Meneses.
In a letter dated 27 August 1481 to Cardinal Paolo di Campofregoso, Sixtus wrote, "From Portugal there are twenty caravels and a cargo ship that we expect on the day at St Paul's, whose leader is a venerable brother Garcia, bishop of Évora".
[2] On 14 September, the very day that the Ottomans surrendered Otranto, the Pope was writing from Bracciano to his vice-chamberlain, who had informed him of the slow progress of the Portuguese fleet.
The next day, he wrote to the bishop and praised him for his diligence and caution but urged him to take his fleet to Vlorë to oust the Ottoman garrison there to do "something worthy of the Christian religion and your honor and that of your king" in reference to the recently-deceased King Afonso V. Sixtus also urged Garcia to take Andreas Palaiologos, the deposed despot of Morea, back to Greece to begin the reconquest of his lands.