In my reading of Heine I came across the startlingly prescient passage:

Christianity, and this is its finest achievement, quieted this brutal Germanic lust for battle to some degree, but could not eradicate it entirely, and if one day that subduing talisman, the cross, is broken, then the savagery of the ancient warriors will rattle its weapons afresh in the senseless rage of the Berserkers of which the Nordic poets tell in song and story. The talisman is rotten, and the day will come when it collapses lamentably; then the old stone gods will arise from the forgotten rubble, and Thor with his gigantic hammer will spring aloft and smash the Gothic cathedrals. When you hear the thunder and crashing, you children next door, you French people, then take care not to meddle in the work being done in Germany; or else it will be the worse for you. Take care not to fan the fire, take care not to extinguish it; you could easily burn your fingers in the flames.

– Heinrich Heine, 1835