SAN JUAN CAPISTRANO, or St. John of Capistran, the theologian and 
preacher, with the Turks threatening southern Europe in 1455:

 "In September the preaching of the crusade began, with Pope Calixtus III 
sending cardinals for that purpose to France, Germany and Poland. The 
Pope's countryman Alfonso V of Aragon and Naples took the cross 
November 1 and agreed to supply 15 galleys for the crusading fleet. 
Afonso V of Portugal, now ruling in his own right, pledged 12,000 men 
for a year. St. John Capistrano, the fiery Observant Franciscan preacher, 
raised men for the crusade throughout Hungary and Transylvania, 
reaching past the aristocracy to the common people.

 "They moved quickly for the age, but except for St. John Capistrano, they 
were still not in time. Muhammad II the Conqueror was a man before 
whom any delay could be deadly. On April 7, 1456 the news reached 
Hungary that he was on the march for Belgrade with a force of almost the 
same size that had taken Constantinople -- about 80,000 men and 300 
cannon. Sixteen-year-old King Ladislas Postumus of Hungary fled in 
panic to Vienna, and many of the once boastful Hungarian nobles 
abandoned Belgrade for their home estates. Hunyadi's field army and the 
garrison of Belgrade held firm, perhaps 16,000 in all; and St. John 
Capistran brought at least 8,000 crusaders with him, though many of 
them were poorly armed and little trained. The odds in favor of the Turks 
were therefore between three and four to one. On June 29, the feast of St. 
Peter and Paul, Pope Calixtus III called on all archbishops, bishops, and 
abbots in Christendom for prayer, fasting and penance for deliverance 
from the Turks, who three days later had fully invested the city of 
Belgrade.

 "July 4 was a Sunday. St. John Capistran said Mass in Belgrade castle, 
and instructed the many priests present not to participate in any way in 
the battle, except by their prayers and assistance to the wounded. The 
odds shook even the redoubtable Hunyadi, who proposed retreat if it 
were possible; Capistran replied that he and his crusaders would never 
leave Belgrade, but would go down fighting to the last man like 
Constantine XI if Hunyadi abandoned them. There was no doubt of the 
total loyalty to the great preacher of the crusaders he has raised; if he 
would stay they would stay, and John Hunyadi would not be outdone by 
them in courage. Instead of retreating he advanced, with 200 boats on July 
14 to win a naval battle on the Danube while St. John Capistran stood on 
the shore praying and holding up a crucifix which Pope Calixtus III had 
sent him. This victory enabled the resupply of the garrison and the city.

 "Belgrade could not now be starved out; it must be taken, if at all, by 
assault. Its walls had been shattered by the overpowering Turkish 
cannon; Hunyadi did not see how they could be defended, and he was 
right. Again he proposed retreat; again St. John Capistran interposed his 
absolute veto. The grand assault began in the evening of July 21 and by 
midnight the Turks had broken into the city at several points. But that 
was not, as Constantinople, the end of the battle -- only its beginning. All 
through the night and into the following day Hunyadi and Capistran 
commanded from a high tower, Hunyadi directing his troops, Capistran 
holding up the papal crucifix. The Christians would not yield; they 
contested every street, almost every building. The Turkish artillery could 
not help the attackers now; the gunners could not see inside the city, 
where they were as likely to hit their own men as the Christians. As the 
sun rose it became apparent that the Christians were prevailing. Some of 
the Turks were retreating back through the breaches; great numbers lay 
dead or wounded in the bloody streets. Turkish attempts to send 
reinforcements into the city were met by masses of flaming brushwood 
flung into the breaches.

 "By noon the city was virtually clear and the Turks were fought out, but 
Hunyadi and Capistran were not done. In early afternoon they 
counterattacked, streaming across the wrecked walls and into the fields 
beyond at a measured pace, with the 71-year old Franciscan in their 
midst, still holding up his crucifix. Hunyadi seized some of the Turkish 
guns and turned them on their makers. An arrow found its mark in the 
Sultan's body; though the wound was not serious, it underscored his 
defeat, and in the evening he was in full retreat, abandoning his camp 
and the city. For the moment at least, the infidel advance had been halted. 
Pope Calixtus III called it "the happiest event of my life".

 "In the full heat of summer the thousands of unburied corpses in and 
around Belgrade rotted and bred disease, and the consequent plague 
carried off both the victors, Hunyadi after only a few days, the lean and 
whipcord-tough Capistran only after three months of struggle. In the long 
sweep of history the victory of Belgrade was of only marginal significance 
for Christendom, but it did hold up the final Turkish triumph in the 
Balkans for a generation -- along with the remarkable fight waged by the 
ex-Muslim and reconverted Christian "Skanderbeg" (George Castriota) in 
Albania, whom Pope Calixtus III in December 1456 named "Captain-
General for the Turkish war," and who maintained a successful resistance 
until his death in 1468. But the triumph at Belgrade shows what might 
have been done by a united Christendom and a great martial Pope at the 
siege of Constantinople.

 A History of Christendom, Vol. III Warren H. Carroll