After the fall of Constantinople, Gennadius was taken prisoner by the Turks. In administering his new conquest, 21-year-old conquering Sultan Mehmed II wished to assure the loyalty of the Greek population and above all avoid them appealing to the West for liberation, potentially sparking a new round of Crusades. Mehmed therefore sought the most anti-Western cleric he could find as a figure of unity for the Greeks under Turkish rule – and Gennadius as leading anti-Union figure was a natural choice. On 1 June 1453, just three days after the fall of the city, the new Patriarch's procession passed through the streets where Mehmed received Gennadius graciously and himself invested him with the signs of his office – the crosier ("dikanikion") and mantle. This ceremonial investiture would be repeated by all sultans and patriarchs thereafter.