The Other War

The Other War is so called not to distinguish it from some better-known war, but because the enemy (of pretty much everyone) was the mysterious Other. The first battle, if something so apparently one-sided can so be called, was an attack on Castle Heterodyne, in which the Lady Lucrezia Mongfish Heterodyne disappeared for reasons still unknown, among many other casualties. The Other primarily targeted Sparks all over Europa, working through revenants, and managed to exterminate forty-three major houses and terrorize the whole continent. Bill and Barry Heterodyne appear to have led the resistance while searching for Lucrezia.

The war ended several years later, concurrent with the Heterodyne Boys' disappearance, but the aftershocks still haven't died away. Leftover revenants roamed the countryside until the Baron returned from exile in a very bad mood (and even after that, there were a distressing number of sleepers), and the disruption of the status quo must have been a major factor in the chaos that prompted him to go conquering.