Sultan Mehmed crushed a Janissary rebellion, executing Ali Haydar and his followers. He then sent Battal and Bali Bey to eliminate bandits, capturing Ferhat’s chamberlain, Beşir, and questioning Ferhat Pasha's loyalty. The Ottoman army attacked Constantinople with the Şahi cannon, creating a breach at the St. Romanos Gate. Despite heavy resistance and losses from Byzantine defenders, the Ottomans continued their advance. The battle's outcome would decide if Constantinople would become Istanbul.