on a crusade owing to pestilence in
his army. The clergy were bidden to assemble in the Church of St Peter
and to fling down their lighted candles as the Pope cursed the Emperor
for his broken promise, a sin against religion. The news of this
ceremony spread through the world, the two parties appealing to the
princes of Europe for aid in fighting out this quarrel. Frederick
defied the papal decree, and went to win back Jerusalem from the
infidels as soon as his soldiers had {16} recovered. He took the city,
but had to crown himself as king since none other would perform the
service for a man outside the Church. Frederick bade the pious
Mussulmans continue the prayers they would have ceased through
deference to a Christian ruler. He had thrown off all the
superstitions of the age except the study of astrology, and was a
scholar of wide repute, delighting in correspondence with the learned.

The Arabs did not admire Frederick's person, describing him as unlikely
to fetch a high price if he had been a slave! He was bald-headed and
had weak eyesight, though generally held graceful and attractive. In
mental powers he surpassed the greatest at his house, which had always
been famous for its intellect. He had been born at Palermo, "the city
of three tongues"; therefore Greek, Latin, and Arabic were equally
familiar. He was daring in speech, broad in views, and cosmopolitan in
habit. He founded the University of Naples and encouraged the study of
medicine; he had the Greek of Aristotle translated, and himself set the
fashion in verse-making, which was soon to be the pastime of every
court in Italy.

The Pope was more successful in a contest waged with tongues than he
had proved on battle-fields, which were strewn with bodies of both
Guelf and Ghibelline factions. He dined in 1230 at the same table as
his foe, but the peace between them did not long continue. In turn
they triumphed, bringing against each other two armies of the Cross,
the followers of the Pope fighting under the standard of St Peter's
Keys as the champion of the true Christian Church against its
oppressors.

Pope Innocent IV, who succeeded Gregory, proved himself a very cunning
adversary. He might have {17} won an easy victory over Frederick II if
the exactions of the Papacy had not angered the countries where he
sought refuge after his first failures. It was futile to declare at
Lyons that the Emperor was deposed when all France was crying out