224 A HISTORY OF THE CRUSADES I 
 
 
 Three months later, the pope was no longer in doubt when he wrote to young
Henry IV, king of Germany: "I call to your attention that the Christians
beyond the sea, a great part of whom are being destroyed by the heathen with
unheard-of slaughter and are daily being slain like so many sheep, have humbly
sent to beg me to succor these our brethren in whatever ways I can, that
the religion of Christ may not utterly perish in our time — which God
forbid." 
 With exaggerated optimism, Gregory told the young king that 5o,ooo men were
prepared to go "if they can have me for their leader," and suggested that
they might "push forward even to the sepulcher of the Lord." Naively, he
even asked Henry to protect the Roman church during his absence. December
16, the pope followed with a general call to fideles beyond the Alps, and
at the same time wrote to the countess Matilda that he hoped she would accompany
the empress Agnes, who was expected to go. But January 22, 1075, when he
wrote to his former abbot, Hugh of Cluny, he made no mention of any expedition
to aid Greek Christians, although he complained that they were "falling away
from the Catholic faith". 
 When Gregory became involved in the desperate conflict with the western
emperor, he had to give up his hopes of winning friends at Constantinople,
and instead of helping the Greeks to repel Turkish invaders, the pope gave
his blessing to an invasion of the empire by Normans. Although he had tried
to check Norman aggression in southern Italy during the early years of his
pontificate, as the letter to the count of Burgundy indicates, he had to
reverse his policy when hard pressed by Henry IV. In 1080, by concessions,
he induced Robert Guiscard to become his ally, and when the Normans prepared
to invade the Balkan peninsula, Gregory gave his support to. this buccaneering
enterprise. He had excommuni cated Nicephorus III Botaniates, who had deposed
Michael in 1078, and Guiscard asserted that he intended to restore Michael,
whose son had been betrothed to the Norman's daughter, to the throne. Although
it was known that the real Michael was living in a monastery, Guiscard exhibited
a Greek monk who pretended to be the deposed emperor. Gregory seems to have
accepted this fraud, and on July 24, 1080, he wrote to the bishops in Apulia
and Calabria that all fideles of St. Peter should aid Michael, "unjustly
overthrown," and that all fighting men who went overseas with the emperor
and Robert should be faithful to them, which obvi ously referred to the pretender.6
When Guiscard's undertaking 
6 Registrum (MGH, Epp. selectae), II, 523—524.