2l6 THE KNIGHTS TEMPLARS
The support of the Holy See helped Otto in his fight
against Philip, but the fortunes of the struggle varied. Six
years after Innocent had declared for Otto, the war was still
being fought furiously, and the advantage had been gained
by Philip of Swabia. The Pope had no intention of backing
the loser in the contest, and he proposed that Otto, in return
for certain territorial concessions, should acknowledge
Philip as Emperor. Otto indignantly refused to abdicate and
quarrelled with Innocent over the proposal. The war was
resumed, but now Innocent had changed sides and assisted the
Ghibellines. When, however, Philip of Swabia was murdered
in June, 1208, and there seemed little likelihood of a new
Ghibelline champion to oppose Otto, Innocent rallied to the
support of the Guelphs once more.
But Otto would not forgive Innocent for his desertion.
He led an army into Italy, forced the Pope to confer the
crown on him, and, on the way back, overran lands which
the Church claimed as its own but which Otto insisted
belonged to the Empire. Further causes of disagreement
arose between Otto and the Holy See, and Innocent made up
his mind to depose the Guelph. He had an excellent candi-
date for the throne in the young Frederick, son of Henry VI,
who would take the place of Philip of Swabia and obtain the
allegiance of the Ghibellines. Frederick was a Hohenstauf en
and as such distrusted by the Church, but Innocent determined
to take the risk of making him Emperor. His championship
of the young aspirant was skilful and successful. The Pope
stirred up rebellion in Germany and Italy against Otto and
won the support of Philip Augustus of France; and on July
27th, 1214, Otto's power was broken at the battle of Bouvines.
A year later Frederick II was crowned at Aix-la-Chapelle.
The Church had raised him to the throne, but he was to be a
menace to the Church throughout his stormy life. Pope
Honorius, successor to Innocent, was soon fulminating
bitterly against the new Emperor. The causes of complaint