Siege of Terra
|Siege of Terra|
|Status||Pyrrhic Loyalist Victory|
|Commanders and Leaders|
|Horus, Angron, Mortarion, Angron, Fulgrim, Perturabo, Magnus the Red, Zardu Layak, Kelbor Hal||The Emperor, Sanguinius, Rogal Dorn, Jaghatai Khan, Vulkan, Malcador the Sigillite, Constantine Valdor|
|Sons of Horus, Death Guard, World Eaters, Emperor's Children, Thousand Sons, Iron Warriors, 5000 Word Bearers, Night Lords, Traitor Army forces, Dark Mechanicum, Traitor Titan legions, daemons||Imperial Fists, Blood Angels, White Scars, Adeptus Custodes, Sisters of Silence, Knights Errant, Imperial Army, three Titan Legions|
|Massive Heretic Astartes casualties, massive Traitor Army losses, massive Traitor Titan losses, massive Dark Mechanicum losses. Horus slain.||Massive military and civilian losses. Sanguinius slain. Emperor mortally wounded and interred into Golden Throne.|
|Traitors driven from Terra and into the Eye of Terror. Death of Horus and crippling of the Emperor. Great Scouring Begins|
The Siege of Terra was the end of the Horus Heresy in Warhammer 40,000. If the Horus Heresy can be considered the most important series of events in the 40k universe, then the Siege of Terra itself could be considered the single most important event. It is also possibly the most fucking awesome event; Brother fighting brother, the mighty guns of Titans blowing fortifications to shreds, Imperial Army soldiers leading charges against the traitorous forces even though they know it's suicide and Ollanius Pius
It was Horus's big attempt to off his daddy and so be the true Emperor of the galaxy (for Chaos of course!). He brought a load of his traitor legions, millions of corrupt Imperial army personnel and mutants, the part of the Mechanicus that had gone over to his side and a whole load of daemons to boot. On his side the Emperor had three legions, his custodians and the loyal imperial army regiments of Terra and you know what? The Emperor went and won anyway (granted it was because the Emperor offed Horus before his legions could crack the Imperial palace but still, victory for the home team!).
The Solar WarEdit
Dorn began fortifying Terra immediately after getting word of the Heresy, knowing that it would always be Horus's eventual goal. Despite being removed from the larger battles of the Heresy, the Solar System was touched by the conflict, with Mars rebelling and numerous sleeper agents and cults trying to destablise the Throne World. Despite this, Dorn managed to do the best he could, turning Terra into the most heavily fortified system in the Imperium. He even managed to blunt part of the traitor advance at the Beta Garmon cluster before getting ready for the final rumble they had known was coming.
Terra was unique in that it that it had two artificial mandeville points inside the the Solar system itself, created during the Dark Age of technology. Dorn fortified the likely approaches from the outer edge of the system and built up huge defences around the two internal jump points. Infiltrators and covert operatives sabotaged loyalist assets across the system. The Iron Warriors were the first Astartes into the breach, sending huge up-armoured Space Hulks as fireships to wear down the defenses, before sending their main fleet through to engage the combined Fists and Scars fleets. The inner system conflict went on for a bit, with the loyalists managing to hold out enough to slow down the advance, at least for a little while.
However, under Magnus's direction, the traitors turned the Shrine of Unity comet into a vast warp gate that allowed Horus, Angron, and Fulgrim's fleets to jump right past most of the rings of defense Dorn had come up with. On the Phalanx, Dorn was preoccupied with a daemon incursion and could do little to stop the huge fleets that were now mobbing for Terra. The Martian traitors, free from the blockade that had hemmed them in for years, joined up with Horus. The Solar War had been lost barely after it had begun. The rest of the Loyalist fleets, knowing they could never hope to fight even a fraction of the vast traitor armada, regrouped on the edge of the system, along with the Phalanx, waiting for the moment they could make an effective strike against Horus. There were early plans for the Emperor to be evacuated to the Phalanx and escape Terra, but these were made by people unaware of what Big E was doing in the basement of the palace.
The Siege BeginsEdit
With orbit uncontested, most of the armada held in orbit above the palace and began bombarding the Aegis, the vast shield network protecting the entire palace. Unlike regular voidshields, the Aegis consisted of multiple overlapping layers of shields that individually regenerated as fast as they could be depleted by bombardment. On the ground, the palace was protected by colossal networks of walls and bastions, static defences, and vast numbers of Imperial Army units bolstered by hordes of press-ganged conscripts. Unknown to almost everyone, the Inner Palace was also protected by a psychic ward generated by the Emperor that would royally fuck up any daemon that set foot near it, daemon primarchs included.
The rest of Terra wasn't so lucky. Barring a few isolated holdouts, the rest of Terra was virtually defenceless. It should be noted that if the goal was to destroy Terra wholesale, it could have been easily accomplished by Exterminatus level weaponary. Perturabo, as the only none Chaos-ifed primarch, grew increasingly angry at what he saw as an irrational and wasteful goal. But Horus was insistent that the Emperor had to be slain in person. So the Palace had to be destroyed the old fashioned way. The Daemon Primarchs were kept in orbit, safe from the Emperor's wards, although this meant that Angron had to be imprisoned in an almost impenetrable maze to stop him from Leeroy Jenkinsing the whole thing.
Hordes of mutants, beastmen, cultists, and traitor army units were thrown at the conventional defenses. Entire wings of aircraft dueled above the Palace. Precision bombardments gradually weakened minute sections of the Aegis long enough for bombers to get through and destroy the projectors. The Dark Mechanicum landed siege camps at 8 points around the palace - partly to surround the palace but also to act as the focus for a ritual that would enable the warp to take a foothold on the surface of the Throneworld. The Astartes were held in reserve on both sides whilst their more conventional forces softened eac hother up. The Death Guard were the first traitor Astartes to land on Terra, with the Khan and the White Scars riding forth on jetbikes and aircraft to meet them and wreck the Dark Mechanicum's siege camps. The Night Lords were the first Astartes to breach the walls of the Palace, albeit in small numbers; this attack also cost them their de facto commander, Gendor Skraivok. Sanguinius himself descended to help the mortal forces, acting as both force multiplier, decoy, and morale booster.
Duel of the Emperor and HorusEdit
Like with any truly epic event, the siege only ended with the most motherfuckingest duel in the entire 40k fluff; the Emperor of Mankind against Horus, most favoured of the Primarchs and the living avatar of the Chaos Gods. If the Horus Heresy was the most important of a series of events, if the siege was the single most epic event, then the duel is the defining moment of the fluff and affected everything else that came after it.
Although the Emperor managed to win and kill Horus, he was so badly wounded in the end he needed to be on 24/7 life support just to survive. So really when you come down to it it was a draw; Chaos had been stopped then but only at an unthinkable cost to the Imperium.
What, besides the fact that it's the most important event in the 40k universe? Fine.
The Siege of Terra is also the theme for the Horus Heresy board game, in which you reenact the Siege itself. There. Happy?
The fa/tg/uy's explanation of the Siege Of Terra (for Dummies and BL Editors)Edit
The main rule of warfare. As the number of combatants increases, the resemblance to complete uncontrolled insanity approaches infinity. And then you have to take into account the terrain...
Basically you start with a planet that's been nuked, polluted, and generally lived-in for a few hundred thousand years too long. And everyone on it is fighting everyone else, constantly. Your basic unit of land is the Bunker, Vault 101 style. There isn't any natural plant life left, of course, so all the oxygen is made in vats with the food. ""Luckily"" this means you can build anywhere that isn't intensely radioactive, and hence fight over those areas. Get Mega-City-One, nuke it and rebuild it a few times, and then you start to understand.
Then the Emperor comes along, and manages against all odds to conquer the place. Suddenly everyone isn't killing and dying all the time, and a population boom happens. So Emps organised the largest set of public-works since the first colony ships. He rebuilds huge areas of the planet, and creates the Imperial Palace, the Astronomican, and a buttload more of cool shit besides. And what he gets is effectively one giant city, the second largest (after Commorragh) in the universe. "Huge" just doesn't do it justice as a description. Neither does "Labyrinthine", "Over Populated", or "Gothic Nightmare". And this New Terra was mostly just thrown over the original foundations of whatever was there, like a pile of gold-bricks onto a rat maze. There are bunkers and emplacements still around that date back to the War Against The Men of Iron and even before.
Then the Heresy came, and the Emperor says to Dorn "Fortify this fucking madhouse". So now everything that didn't have a gun emplacement before does now, everywhere. And he walled in half the doors and windows, put hundreds of AA batteries on every roof, filled entire rooms with concrete just for a bit of reinforcement, and generally panicked because if they would only ever be necessary if the space defenses (the best in the galaxy bar none) have failed.
Then Horus arrives in orbit. He's punched through the space-defenses at massive cost, but the war in space is far from won, and the Palace is just a flat no-fly zone, so he can't just pick and choose landing areas. So he bombards everything his ships can reach, fills the sky with Drop Pods, and tries to march on it.
Which is when Rule #1 kicks in and everything immediately gets Mega-Fucked, for both sides. Ruined streets and bunkers make navigating a nightmare, communications are somewhere between impossible and actively detrimental, Drop Pods land off target, plans and back-up plans fall apart in seconds, demons run amok. And the Primarchs are either constantly trying to out Tactical Genius each other or are too in the thick of it to relay any commands, so no-one has a fucking clue what's actually going on in the big picture. It's Stalingrad writ large, but without even the merest hint of sanity, and a thousand space marines charging into every breach. The inclusion of cackling daemons, rampaging renegade guardsman, and bellowing daemon engines doesn't help the situation.
So it takes roughly 10 minutes of this menial bullshit for a load of the Chaos forces to get bored and just decide "Fuck It, Let's Just Wreck The Place". So now everything makes even less sense, entire companies ignoring sensible objectives to go on the Chaos Marine equivalent of a bender. The Emperor's Children and Night Lords rape, murder, and pillage the civilians of Terra so hard that even 10,000 years later they still live in fear at the memory, while the World Eaters hack and slash at anything they think might bleed. Only the Iron Warriors, the Death Guard, and the Sons of Horus are whole-heartedly tearing at the palace, dedicated to rubbing it in Dorn's face like a bitch no matter what. And to the horror of the loyalists, they're succeeding. Brick by brick the greatest military stronghold in the galaxy is falling.
Which sounds great for Chaos, were it not for the simple fact it wasn't falling quickly enough. It was taking days to advance inches at massive cost, and Guilliman was en-route with reinforcements, with Russ and the Lion and the remains of their Legions right behind him. If the siege wasn't ended before they got there, the traitors would likely lose. So Horus put all his cards on the table and lowered his battle barge's shields, goading the Emperor (who didn't know about the reinforcements) on-board to hopefully kill him and force the defenders to rout. Everything else is history.
The short story "The Board is Set" seemed to indicate that the Emperor and Malcador knew about the reinforcing loyalists from at least the beginning of the siege. It also seemed to imply that Horus lowering his shield may have been so he could teleport down and attack the Emperor, not realising it was Malcador on the throne. Possibly the most epic level of Just As Planned.