Rainald’s withdrawal. The duke withdrew to the fastness of Sulmona,
which was besieged by John and Colonna. However, the Church’s war
effort was already beginning to judder under severefinancial strain. Pope
Gregory threw his last reserves into the Abruzzi, including John’s former
sparring partner, the legate Pelagius. Pelagius promptly appealed to John
and Colonna for help, and the various papal forces managed to converge
near Capua. Their sole remaining trump card was the absence of
Frederick II, though, and this, too, was nullified when the emperor
landed at Brindisi on 10 June 1229. Well aware of what was happening
behind his back, Frederick had needed a quick triumph in the East, and
so he had leapt at the kind of treaty that the Fifth Crusade had twice
turned down. In this way, however precariously, he won back the holy
city of Jerusalem. The emperor’s return, under such circumstances,
tipped the balance decisively. The forces of the Keys utterly disinte-
grated. In some ways, as many commentators have gleefully noted, it
was a re-run of the end of the Fifth Crusade. John was again unable to
prevent a military collapse in the company of the‘ill-starred’Pelagius.^166
Staring defeat in the face, John secured the pope’s permission to quit his
offices in Italy and return to France, but he was not going there to retire.
Instead, he was beginning a new task: to raise men and money for his
proposed expedition to Latin Constantinople.^167
The Latin empire of Constantinople had been founded following the
diversion of the Fourth Crusade. A Franco-Venetian army of crusaders
had captured and sacked the city in 1204. Yet the‘replacement empire’,
which they established on top of Byzantium’s ruins, was in serious
trouble almost from the very start. By the beginning of John’s reign, the
main external threat was the rival Greek‘empire of Nicaea’, under John
III Doukas Vatatzes. The rightful heir to the Latin empire, in 1228, was
Baldwin of Courtenay, one of John’s kinsmen through marriage. He
was only around eleven years old, though, and so a regent was needed–
preferably a powerful outsider who would bring in the aid and assistance
that was so desperately required. An interested party, who in some ways
fitted the bill, was the Bulgarian ruler, John Asen. On paper, at least, he
was in communion with Rome, and so a deal was struck, confirming that
he would be the regent. It foundered before it could be implemented,
though, converting him into another enemy.
John was the obvious Western candidate to replace Asen, given his
past experience as king of Jerusalem. An arrangement was made quite
(^166) The quote is taken from T. C. Van Cleve,The Emperor Frederick II of Hohenstaufen:
167 Immutator Mundi(Oxford, 1972), 229.
For John’s role in the War of the Keys, see Perry,John, 144–9.
70 Breakthrough and High Point (c. 1191–1237)