There were good reasons for canceling the expedition. Originally, 1481 had seemed like a good time to strike as the Ottomans had recently suffered a series of reverses. In August 1480, they had been repulsed with heavy losses in the siege of Rhodes, and Mehmed II's death on 3 May was followed by a civil war between his sons Cem and Bayezid over who was to seize power. Andreas may have hoped to take part in a counterattack against the Ottomans led by Ferdinand I (who was at the time being attacked by the Ottomans at Otranto). By October, the situation had grown unfavorable: Bayezid was well-established as Sultan and the major Christian realms of Western Europe were too disunited to join together and wage war on the Ottomans. More critically, Andreas's efforts were underfunded. Historians, following the writings of contemporary writer Gherardi da Volterra, have alleged that Pope Sixtus IV gave Andreas 3000 ducats to finance the expedition. Though the sum was paid to Andreas in September 1481, there is no evidence to suggest it was for the war in Greece. English historian Jonathan Harris believes that it is more likely that the money was simply an advance payment for his travels in southern Italy since it did not cover any extra costs outside the regular expenditure of Andreas and his household.