Casting Islam as paganism let crusaders frame their war as revived martyrdom.

Evidence

If Islam is seen in the familiar and despised guise of ancient paganism, then the struggles of Christians against it will be seen as part of the continuing struggle against the pagan persecutions of Roman days. With the notion of opposing paganism, naturally came the ideal of martyrdom: the chroniclers compared the struggle with the “pagan” Saracen to the struggle against the ancient pagans of Rome. — John V. Tolan, Saracens, 664

Categorization

• XREF: Relates to how political communities reframe current enemies as reincarnations of older, known adversaries — a pattern visible in contemporary ‘new Nazis’ and ‘new Cold War’ rhetoric.