Hey, I thought of one of those stupid questions, and if the Internet has taught me anything, it's that if you have a dumb question, posit in on the Web (that, and a lot of people are really crappy people, but... ) Anyway, here's the one that spawned this thread, along with a certain amount of exposition.

So, Holy Terra is a VERY critical location in the Imperium, but it has no Space Marines; there might be some Imperial Fists, or something, but Humans on Terra seem to have an almost genetically-inherited fear of Space Marines, from the time of the Heresy, so there is no Chapter to shield the Throne. We do have Adeptus Custodes, but they don't guard Earth; they guard Him on Earth's Throne. Battlefleet Solar and the Luna Defense Garrison can protect Holy Terra, but if something gets to the ground? They could have some Arbites, but they manage law (for what passes for people on Earth), not fight invasion. So, does Holy Terra have a named regiment of Imperial Guard, or some such? Who bears the primary job of protecting the land that spawned Mankind? With no more valuable target, I wonder why there is no regiment of Terra, in the likely event that there isn't one.

Well, there's a unit called "Terran Praefects" - 10 regiments of which were sent to Armageddon to reinforce Imperial positions. They don't show up in the first Force Disposition Chart that was printed in White Dwarf and the rulebook, but in this little known follow-up list that documents the forces of the second wave after the culmination of the Season of Fire.

I have no idea if they've ever been mentioned anywhere else, or if the name really means they are from Terra, but I suppose it's a start.

I would expect Holy Terra to have a formidable PDF supported by extensive gun batteries and countless squadrons of fighter craft. Terra is also the seat of the Convent Prioris of the Adepta Sororitas, and home to three of the six Major Orders Militant, though even thousands of Battle Sisters (most of whom are going to be on various off-world assignments anyways) are merely a drop in the ocean compared to the regular forces that are bound to be standing ready to repel invaders or suppress unrest.

I honestly doubt that Terra has it's own dedicated PDF, simply because I have a hard time envisioning any form of real society on Terra that would support one. Who would you pull the from? The decadent nobles or the massive clerk-hordes of the Administratum?

I am only musing, but I would imagine that Terra would have millions of soldiers from various corners of the galaxy at any one time, likely primarily in orbit aboard the massive barges of the Imperial Navy. In addition to that, the planetside Adeptus Arbites probably have multiple precinct-fortresses. Also, remember the scores of Schola Progenium soldiers and specialist being trained on Terra at any one time.

Add to that the forces of the Scholastia Psykana. Yes, not a fighting force per see, but more than formidable when push comes to shove. The Adeptus Custodes, as well, are to Space Marines what Space Marines are to man, each one of them an individual investment likely capable of destroying minor cities, given enough time to pound on things.

The aforementioned Adepta Sororitas and the forces of the Ecclesiarchy, as well.

Along with Mars and the Lunar defences, I don't think Terra will be in any danger anytime soon, save from perhaps Necrons or Tyranids. Or if that gate behind the Golden Throne fails.

I honestly doubt that Terra has it's own dedicated PDF, simply because I have a hard time envisioning any form of real society on Terra that would support one. Who would you pull the from? The decadent nobles or the massive clerk-hordes of the Administratum?

The following is just my interpretation, but I'd figure that even Terra has a "normal" citizenry in that not everyone is a noble or a clerk. Whilst those occupations may be unusually bloated on this world compared to others, there's bound to be countless families whose members are merchants, public transport operators, law enforcement, construction workers, Ecclesiarchy clergy (including the Ecclesiarch himself) and their lay servants, repair guys, courtesans, ...

I mean, even if we assume that all production of foodstuffs and vehicles etc happens elsewhere, there are still so many jobs attached to just distributing these goods and keeping the buildings from collapsing, etc. And I'm fairly sure even Holy Terra has a vast underworld that is just as grim and decayed as Necromunda's. If we look at the Imperium of Man as being inspired by the Roman Empire, then we can also look at the city of Rome.

A statement like "all of Terra is clerks" kind of sounds like "Mars is populated only by Tech-Priests" - yet the Fabricator-General has his own Tech-Guard anyways.

Besides, if you want a standing military on Terra, you'd just draw them from the same source you draw the clerks from. The question is really just whether you want a PDF or not. And personally, I'm assuming the Codex fluff about the Imperial edict on planetary defences to apply to Earth, too.

Speaking of GW fluff, I also just remembered something from Inquisitor:

Never been a fan of those OTT high fantasy interpretations ... but that's a matter of taste, of course.

Who bears the primary job of protecting the land that spawned Mankind? With no more valuable target, I wonder why there is no regiment of Terra, in the likely event that there isn't one.

The Imperial Fists claim the honor. Terra is their Homeworld after all (previously Inwit, but screw that place)

Who bears the primary job of protecting the land that spawned Mankind? With no more valuable target, I wonder why there is no regiment of Terra, in the likely event that there isn't one.

The Imperial Fists claim the honor. Terra is their Homeworld after all (previously Inwit, but screw that place)

I assume most are aboard the Phalanx, or in various warfronts, prosecuting the Emperor's endless wars; they are too few in number to guard both the Emperor's world and His words "it all belongs to Mankind." Also, I doubt they draw neophytes from Terra's population.

Yeah, I sort of forgot the ST regiments and the SoB's, my bad.

The Imperial Fists claim the honor. Terra is their Homeworld after all (previously Inwit, but screw that place)

This may require further clarification - I've taken a look at the Index Astartes, but all it says about the Imperial Fists is that they are a fleet-based Chapter which recruits from all over the Imperium, and that their headquarters is a mobile fortress called "Phalanx".

"The willingness of Dorn to put his initial misgivings aside and embrace the Codex Astartes reassured the High Lords of Terra. Because they were not tied to a home world and had a mobile Chapter Fortress, the Imperial Fists could be more responsive to calls for help. In particular, Rogal Dorn was more amenable to requests from other institutions for assistance than other Primarchs, and this built a valuable store of goodwill. [...]"

They might have one of their little emissary-chapels on Terra, though, and draw recruits from there, much like they do from Necromunda. This isn't actually said anywhere, but it seems to be likely? Has there ever been more detail on this subject, preferrably from a GW source? Or is this contradicted in other sources of fluff?

[edit] eldar'd!

No worries, the ST regiment thingie was just a little theory of mine, and everyone forgets the SoB, even GW.

[edit #2] Thinking about it .. it kind of would be cool if Terra had some sort of edict against the presence of Space Marines, like ancient Rome and the Legions - this would basically make acts such as the four Marine Chapters that landed on Terra to fight Vandire a bit like "crossing the Rubicon"...

(there probably isn't anything like this, though, I'm just thinking it would be an intriguing detail)

There was an Imperial Fists fortress-monastery listed as one of the regions on the map in the Horus Heresy board game (set in and around the Imperial Palace). It's on the west, between the inner palace and the eternity wall spaceport.

All that's left of it now is the Column of Glory/Column of Heroes/etc (name varies a bit in different sources) which is basically a memorial column with suits of Astartes Armour from the heroes of the siege set into it.

I'm pretty sure the adeptus astartes broadly speaking aren't permitted on Terra (there are individual representatives, pilgrimages, and astartes who aren't serving their chapters directly). Can't remember where that's from but I know I've read it. Which makes sense, given what a mess they made of the place the last couple of times they visited....

Defence forces of Terra:

• It's a hive world. So a PDF (possible the aforementioned Praefects) which befits such a world (i.e. huge)
• Various private armies belonging to the nobility and (especially) the navigator houses. Taking Belisarius as an example, they've got about a third of a line company of astartes in the form of the Wolfblade.
• There's the Legio Ordo Sinister. Who get used off-world but are based on Terra. It's a 12-engine legio - but they're all Imperator-class.
• I think one of the main Sororitas Convents is on Terra? So that's three full militant orders.
• The Inquisitorial Fortress in antarctica. This is the central fortress of the Ordos in the Imperium, and will be guarded by what we shall call "some" stormtroopers, plus it probably serves as a watch-station with deathwatch kill-teams on hand.
• The Adeptus Arbites. This is a - is the - High Precinct - so you'll have Arbites forces present in regimental-plus strength.
• The officio assassinorium - all but one of the assassin temples is based on terra.
• The Adeptus Custodes - it's never been made entirely clear how many there are of them, but let's be fair, even a few hundred is a terrifying threat.

The Fist's 'homeworld' is indeed the Phalanx. Which is also relevant, depending on the background you want to follow. In the novels Phalanx and Sons of Dorn, it cruises round the Imperium, dispatching forces to trouble spots.

Ward decided that previously written background could go disappear up its own backside, and instead said that Phalanx just sits in orbit of Terra, because apparently it's broken down and no-one can fix it. Except it's still able to jump into the warp within minutes from inside terran orbit with no preparation required when a daemon incursion occurs inside the ship. If you haven't read Sentinals of Terra, don't ask, just smile, nod and erase this paragraph from your mind. It's a real triumph of background writing. I particularly like the part where Lysander is taught a valuable lesson about not being an arrogant, vengeance-obsessed tool by some sound advice given by Captain Sicarius of the Ultramarines and Captain Tycho of the Blood Angels.

The Wolfblade portions of the Space Wolf novels are set largely on Terra, they describe in as a hive like any other albeit planet wide and with far better policing in the top to mid levels.

In short Terra is a heaving hive-hell ruled by teeming billions of clerks, administered to by billions of clergy and supported by countless more servants, merchants and oddjobbers who are prey upon by criminals and deviants and crushed by Arbites and Custodes and that's just on the levels people like to think about.

Imagine Coruscant with smog, washed by acid rain and terrorised by the policing of overzealous militants.

Terra's defences are easily estimatable as "Formidable".

You'll have some Imperial Fists and Space Wolves as mentioned, plus Astartes from their agreements with Navis Nobilite assuming similar arrangements exist. Battle fleets Luna and Solar patrol the Sol System's void. You'll have Guard regiments, Black Regiments, Legio Sinister, Adeptus Custodes, the halls of the Oficio Assassinorum, the privatised military might of the Terran Nobility, 3 Militant Orders of the Adeptus Sorroritas, Arbites, Grey Knights and much much more.

As much as Terra on its own is pretty much overkill with, depending on source, up to a complete legion of Custodes entrenched in the greatest and strongest fortress-palace of the empire, Mars seems to be the Planet for sheer firepower. The Battlefleets became kinda lazy in the last time though the AdMech formidable demonstrated that there is no kill like overkill when the small Necron force arrived.^^

What makes me wonder his how fast they actually responded to that "threat".^^

The raw power of Terras Defense are a relic of older Codex times where the entire war was more or less a stalemate and every faction required their own kind of "invincible base". The Chaos had its Eye that was not really attack-able, the Empire had the Sol System, the Tau had the plot armor that regularly forced lager enemies to draw their attention, Necrons and both Eldars were superbly hidden.

That ofc was before the days when Doomsday weapons became more common than anything else and the insane Fluff-Buff our friendly bugs the Nids received after they became the real threat instead of the actual arch enemy Fail-Baddon and his Chaos-Dudes. (Could be a Boyband)

Don't forget that the Grey Knights have their main fortress monastery in the Sol system. True, they aren't on Earth but they are close enough to provide assistance AND SO IS MARS.

If the attack is coming to the Sol system the attackers will be facing the forces of the two most well guarded planets in the Imperium, there are ships and battlestations, probably much more than other systems have. AND there is a constant traffic in and out of the system:

-Trade ships for the Navigator houses, nobles who live on Terra, Rogue traders visiting Terra etc.

-Imperial fleets sending ships to and from Mars (Mars shipping out the ships and other tools of war that the Mechanicus is building.)

-Sororitas, Arbites, Inquisition and other imperial organisations have fighting capabilities.

Well, I would not count the GK as a defensive force (Only their Fortress and its Garrison). They are more often somewhere in the galaxy than actually on Titan. And even if so it would be the fraction of a Brotherhood. Sure they might be able to field some additional Terminator-Squads if you are lucky but if we start talking about a Legion of Custodes this is not actually much. Same counts more or less for the Inquisition. They might have some Garrison Troops and Kill Teams in Reserve but the vast majority of the really skillful personnel is scattered around the galaxy. And some Inquisitors of their own are not what I'd call a fighting force. But if we consider Support like Target Recon etc they might have some role to do.

Counting all the Minor Forces like the Wolf Guard or some other Honorary SM Squads is nice but unless they are the protagonists of a "Defend Terra" Novel they would not do much.

So I'd stick with some kind of Elite PDF, Hordes of Arbites and SoB and Finally the Custodes that, if some parts of their fluff are true, could hold any kind of army known in the entire galaxy as long as there are not to much greater war machines though the imperial Palace should count as a war machine of its own. Count in the obligatory Emperor Titan Legion and we are set.

And then we have the frenzy of untold numbers of imperial citizens, living on the most sacred of worlds, glad to give their life for the emperor... actually... I like the idea of some up scaled (everything on Terra must be up scaled^^) Hive-Gangs that would make high nobility on lesser worlds, joining the fray. xD

Well, I would not count the GK as a defensive force (Only their Fortress and its Garrison). They are more often somewhere in the galaxy than actually on Titan.

Yeah, same for the three Major Orders of the Convent Prioris on Terra.

"Two and a half thousand years later, two more Orders were created by Deacis VI ( the Orders of the Bloody Rose and Sacred Rose) and the Convent buildings were extended to accommodate almost 15,000 warriors each. In recent years, the number of the Militant Orders' members has declined slightly and each Order now numbers between 3,000 and 4,000 Battle Sisters, of which perhaps 500-750 will be trained as Seraphim.These warriors are spread throughout the galaxy in various battle zones and on extended tours of duty. The size of an Order waxes and wanes irregularly, depending on the quality of recruits availble and battle losses. On occasion an Order may number no more than a few hundred warriors, all fighting the enemies of the Emperor while at other times it may reach a peak of six or seven thousand warriors, with much of the Order fighting in distant wars but still leaving a reserve of several thousand Battle Sisters and Seraphim that can be despatched if needed."

Although I'd say it is likely that there is a Minor Order of a couple hundred Sisters existing for the sole purpose of defending the Ecclesiarchal Palace.

However, given how FFG has inflated their numbers, I suppose it also depends on whether you want to stick to Codex or the (retconned) Dark Heresy fluff?

Well, with inflated numbers I guess there would be a ton of SoBs at Terra, so yea, it boils down to what you want to refer to... again,^^

But at last I would expect some sort of honor Guard to be in the hundreds. There might be such stuff like Crusaders but after all the SoB are THE fighting force of the eccclesiarchy besides Joe the Confessor who somehow found an eviscerator to clean his teeth.

So in conclusion: The warmongering imperium of man has some nasty garrison that ultimately will crush any opposition for the mighty Chaos Gods of GW have decided that this product line may never end.^^

Indeed! Though I'd argue you already mentioned THE fighting force of the Ecclesiarchy in your last post - said "untold numbers of Imperial citizens", roused to pious zeal by the raving ministrations of the clergy.

Well, these do not appear on my force organization chart,^^

To quote a great "tactician" of older times in the tactica imperialis: "good enough to toss; food for powder, food for powder; they'll fill a pit as well as better [men]..."

At last that is in my version.

As we're tallying military forces guarding Terra, a few more speculative thoughts:-

-The Terran system has been inhabited by a powerful spacefaring race for 38,000 years by 40k. As such just the planetary system alone likely has more space stations, star forts, warp bastions etc than the average Imperial Sector. These would likely cluster in near orbit, far orbit and Legrange points around Terra, and also offer defence in depth by lining all conceivable approaches to the planet in vast concentric rings. There's probably a wide range of military forces operating these stations: probably dominated by the Battlefleet Solar, but there are likely many other agencies who own orbital "real estate" in the Sol system. Many of these stations will be truly ancient, some likely predating the Imperium, and one imagines they're almost impossibly tough nuts to crack militarily.

-Luna (the moon) is likely riddled with defensive fortresses. I know the silent sisterhood of the Heresy era had a fortress there (likely suborned by later Imperial agencies) and the moon was also a major centre for genetic engineering; many labs supporting the Legions were based there.

-There's also the Ordos Custodum and Scriptus, two whole Inquisitorial Ordos based on Terra, totalling around 56 Inquisitors and support staff, a total which excludes the staff of the Master of the Inquisition, which is likely far more numerous.

--Mars is, as has already been pointed out, a massive military powerhouse in its own right. The Imperial Navy uses it as the fortress of the Segmentum Solar, the Legio Ignatum is based there (among other Titan Legions) Knight House Taranis calls Mars home, there's the Ordinatus Mars, and given the size & importance of the Forge World, the associated military forces (called Taghmata Omnissia as of 30k) locked in feudal service to the various senior Magi likely run into their billions.

-Each of the High Lords of Terra (plus associated figures like the Paternovae) are likely guarded by private armies the size of a mid-ranking 21st century state, tens to hundreds of thousands strong, if only to "keep up appearances" as a major political player.

-As for PDF, I'm sure Terra would have one. The population of Terra is likely vast, possibly in the high hundred billions or even higher than a US trillion (one thousand billion.) it is the original hive world and the resources of the Imperium pour into it, so the Terran PDF could conceivably be extremely well resourced for a PDF, especially given the proximity of Mars. And there could be hundreds of millions, or possibly even billions of them.

-We don't know the size of the Adeptus Custodes, but they are often described in the 30k material as the "Legio Custodes", so it seems logical to speculate that they might approach the size of an Astartes Legion. Astartes Legions seemed to vary from about 40,000-250,000 strong. My gut feeling is that the Custodes would be a smaller force numerically than a full Astartes Legion (I have no source for this, it just "feels" right). I'd guess 20,000-25,000. I know that seems a lot, but I'd imagine that as of M40 they'd want enough resources to be able to easily defeat a renegade Astartes chapter at full strength at the very least.

-Magnus Grendel mentions that the Astartes probably aren't too welcome on Terra; I can't remember a canon source for this either, but it FEELS correct. However, this certainly doesn't mean that Astartes chapters would fail to defend Terra: I reckon marines play an active role in the planet's defence, just at something of a remove. One imagines that all major warp routes to the Sol system are heavily guarded at the other end by a mix of Naval and Astartes personnel. There are probably marine chapters ringing the Sol system, with a host of fortress monasteries based in planetary systems a single warp jump from Terra. There are also likely regular Astartes visitors to Terra (petitioning for resources, doing homage as auditori imperator like Nisk Ran-Thawl, collecting/depositing geneseed etc). Plus there's at least one chapter (The Minotaurs) who act as agents of the High Lords. No doubt there are other such chapters who occasionally visit their masters.

In short: everyone.

Directly or indirectly agency in the Imperium of man guards Terra, it`s pretty much the whole point of the might of the Imperium. Th Sol system is the only non-expendable asset the Imperium holds, everything else would just be a regrettable loss. Sol`s loss would be a deathblow.

Hah, totally wasn't looking for this, but I just found another tiny reference to that regiment's name in an old issue of Citadel Journal (#49), in an article featuring what could best be described as Proto-Repentia, or more specifically a short story accompanying the fluff and rules:

Well, I would not count the GK as a defensive force (Only their Fortress and its Garrison). They are more often somewhere in the galaxy than actually on Titan. And even if so it would be the fraction of a Brotherhood.

Certainly they are split up and have troops all over the Imperium ready to respond to daemonic threats but you are missing few important bits.

a) Titan has their main chapter fortress and it is the biggest GK base AFAIK. All space marine chapters have most of their marines going on a crusade or other attacks most of the time but Titan is the place where you are likely to find the most GKs who aren't on a mission.

b) Titan is the most likely base where to find the GK leadership and chapter masters. Being marines these are also the most experienced and among the finest warriors in the chapter.

c) If the attacker happens to be chaos and therefore is likely to have daemons the Grey Knights are the most effective troops against them that the Imperium has. Particularly since "let's just Exterminatus the planet and never come back" is not likely to be an option even if daemons are set loose on Terra.

d) My main point was that forces like GK and Rogue Trader troops and whatever are ALSO defending the Sol system. The system has its own defensive forces just for that purpose (some of which is really over the top like the two titans that are stationed on the sides of the door leading to the Emperor's throne room. Apparently the titans are functional despite looking like statues and have a crew just in case they need to smash their way through the wall that they are partially embedded in and start kicking ass.) but it ALSO has troops and ships that simply happen to be there and will also take part in any defensive battle.