From every part of the capital they flowed into the church of St. Sophia. In the space of an hour, the sanctuary, the choir, the nave, the upper and lower galleries, were filled with the multitudes of fathers and husbands, of women and children, of priests, monks, and religious virgins. The doors were barred from the inside, and they sought protection from the sacred dome. Their confidence was founded on the prophecy of an enthusiast or impostor that one day the Turks would enter Constantinople, and pursue the Romans as far as the column of Constantine in the square before St. Sophia, but that this would be the term of their calamities. An angel would descend from heaven with a sword in his hand, and would deliver the empire with that celestial weapon to a poor man sitting at the foot of the column. “Take this sword,” would he say, “and avenge the people of the Lord.” At these animating words, the Turks would instantly fly, and the victorious Romans would drive them from the west, and from all Anatolia, as far as the frontiers of Persia.

From Edward Gibbon’s The Decline and Fall of the Roman Empire, London: Wordsworth, 1998 (first published from 1776 to 1788), p. 1014.