Page 654

654 A HISTORY OF THE CRUSADES 
pontiff seized the opportunity to insist on the conversion of the Greeks
to Roman obedience. The Greek delegation, headed by em peror John VIII and
patriarch Joseph II, was received with honor by pope Eugenius IV and his
cardinals at Ferrara in March 1438. Prolonged discussions took place between
the two parties, who moved to Florence on February 26, 1439. The Greeks were
at a disadvantage, and eventually John VIII and Joseph II (before his death
on June 10), together with a multitude of eastern Orthodox prelates, gave
way to the Latins in regard to doctrinal differences and to the primacy of
Rome, "saving the privileges and rights of the eastern patriarchs." The bull
"Laetentur coeli" of July 6, 1439, was the official proclamation whereby
Constantinople was reconciled to the Roman see. In return, Eugenius signed
a treaty in which he agreed to reinforce the defense of Byzantium with two
galleys and three hundred men annually, and to increase his contribution
to twenty galleys for six months or ten for a year in case of imminent danger.
He further promised to promote the cause of holy war at the courts of Europe.
But the unionist movement was evidently a matter of diplomacy and not of
faith, and as such, it was foredoomed. Neither was the pope able to carry
out his promises and reanimate the crusading spirit among Catholic princes,
nor were the Greeks able to forgive and forget the sins of the Latins in
the Fourth Crusade and after. Finally, the Greek patriarchs Philotheus of
Alexandria, Doro theus of Antioch, and Joachim of Jerusalem allegedly condemned
the Ferrara-Florence compromise and accused their colleague in Constantinople
of heresy; their resolutions were supposedly issued in a common encyclical
in 1443.11 
 In spite of the hopelessness of the situation in western Europe for the
crusade, the reign of Murad II brought Ottoman rule in the Balkans almost
to the edge of disaster. This was due mainly to the heroic career of John
Hunyadi, the regent of Hungary and voivode of Transylvania, who led the Hungarian
crusade with varying fortunes against the Turks. In 1438, Murad had already
crossed the Danube and invaded Transylvania as far as the gates of the strong
town of Hermannstadt (now Sibiu). Meanwhile, his westerly irruption into
Serbia was arrested before Belgrade. At this moment Hunyadi ap peared on
the scene and succeeded in forming a coalition with two other outstanding
eastern leaders: king Vladislav III of Poland 
11. Doubt has been cast on the authenticity of this condemnation by Joseph
Gill, "The Condemnation of the Council of Florence by the Three Oriental
Patriarchs in 1443," 
Personalities of the Council of Florence, and other Essays (Oxford, 1964),
pp. 213—221. On the council in general see above, pp. 92—95,
and Gill, The Council of Florence.