Calth is a very unique situation for the Horus Heresy books. It stands as the first moment one of the traitor legions openly attacked a loyalist faction, and utilized the corrupted “powers of the warp”, or in other words used terrifying space demons for the first time in Chaos’s history fighting against the Imperium. It marks not only the true beginning of the civil war, but also the true fall of the traitor legions, and of humanity at large. What was once thought inhumane, and impossible to contemplate has now become the norm of operations for the galaxy in the plot.
It is not just that this is a civil war now, it is a clearly indentifiable struggle between good and evil, and the survival of humanity. Like Tolkein painted good and evil in broad strokes with the images of the twisted, and tortured elves he called orcs, here we see the “daemons of the warp”, and the physical corruption of the traitor legions as a signifier for evil, or a force that seeks to disrupt the progress of humanity.
Calth was a brutal battlefield that saw their sun become a super nova, and the already beleaguered forces of the loyalist Ultramarines(Caught completely off guard, and they believed they were about to set out with the Word Bearers legion, not be betrayed by them at the staging grounds.), once the largest legion ruling 500 worlds as their own mini empire, had to fight above ground in the radiation, or away for it in the darkest of the planets mining tunnels beneath. The fight stretches the length of two novels in the Horus Heresy series, and is considered the largest depicted engagement between “chaos” and the Imperium in the fictional history.
If you consider the Isstvan V drop site massacre as an allegory for the outright horror of an event like 9/11, then the battle of Calth is allegory for the second gulf war. An extended slog through unknown, and brutal terrain that saw both sides win nothing but a high body count.
unappliedsemantics 