The Thirty Years' War - brutality grew from religious beginnings.

The Thirty Years' War began in 1618 Bohemia, initially a conflict, as most wars are, with religious motives between the upper classes, Catholics and Protestants. It was instigated by the inflexibility of monarchs and the mistrustful and aggrieved aristocracy.

Within only a handful of years, the battlefront expanded, moving west into Germanic Margravate of Brandenburg, the Electorate of Saxony, the Palatinates and beyond. And with its spread grew the brutality and the atrocities - the indiscriminate torture and murder, the rape of both the populous and their land; hanging, burning, maming, quartering, beheading. And after the mercenary soldiers, after the ruthless and savage devastation, came the plague.

By the end, half of Central Europe's population had disappeared.