A Terminator’s left shoulder carries a lump of stone. The Crux Terminatus is carved rock sitting on top of heavy-gauge plasteel, shaped adamantium and a ceramite ablative layer, and it’s the oldest-looking thing on a suit that forge worlds have been refining since before the Heresy. I’ve painted a lot of them and I still think it’s the best design decision on the model.
The claim attached to that rock is enormous. Every one is supposed to contain a fragment of the armour the Emperor was wearing when Horus put him down.
White Dwarf #304, from April 2005, gives the fullest version I’ve found. The Emperor leads the attack on the Warmaster’s battle barge, comes face to face with Horus, and is grievously wounded. Then, in the magazine’s words: “it is said that the Emperor decreed that his armour be taken off and melted down, and that the pieces be made into badges that all Terminators could wear in recognition of the service performed in the defeat of Horus.”
GW did the maths on the Crux Terminatus itself, in 2005
The very next sentence in that White Dwarf is the bit nobody quotes. “However, if this is true, then each suit of Terminator armour must only contain the most minuscule of fragments.”
Same paragraph. The magazine tells you the relic story and then, without waiting for a fan FAQ or a designer’s note eighteen years down the line, adds the caveat itself.
And the caveat earns its place. A thousand Chapters, give or take, each with a First Company that the Codex puts at a hundred veterans. That’s a hundred thousand badges before you count ten thousand years of dead wearers, before you count suits destroyed and replaced, before you count Chapters founded, wiped out and founded again. One suit of armour. The Adeptus Mechanicus is good, but it isn’t doing loaves and fishes with a crucible of ceramite dust.

Something else falls out of the 2005 wording. It puts the melting down after Horus is beaten, which means no Terminator wore a Crux during the Heresy itself. Every Cataphractii and Tartaros suit that fought at Isstvan or on the walls of Terra had a bare left shoulder as far as this badge is concerned. The badge is a memorial, issued once the fighting stopped, which is a slightly different sort of object from the ones a Chapter keeps in its reliquary.
What’s in the box this week
Games Workshop put the Codex: Space Marines pre-order spread up on Sunday. Three versions of the book, and the Limited Edition ships with six swappable metal cover badges carrying the icons of the more codex-compliant First Founding Chapters, six art prints, the full Command Pack, and a metal Crux Terminatus. There’s a dice set too: sixteen dice cast in silver with black pips, with a stylised Crux on the six face.
So the relic is an object you can own now, in metal, at limited-edition-rulebook money. I’ve already been through the six chapter badges and which Chapters didn’t make the cut, so I won’t go over that again.
The preview didn’t actually put a date on the codex pre-order, which is mildly annoying if you’re the sort of person who plans a Saturday morning around refreshing a web store. The only hard time given in the whole article is for the Helbrecht: Sin of Hope Special Edition, which goes up on Wednesday 23 September at 3pm UK time. Everything else is “throughout the week.”
1989, and one captain’s badge
The oldest version of the story is older than I am by a couple of years. It turns up in White Dwarf 112, in 1989, alongside the original metal Terminator squad.
I haven’t got a copy. What I have is Larry Vela’s run-through of that issue on Bell of Lost Souls from last October, which reproduces the pages, and his reading is that the 1989 text attaches the fragment specifically to a Terminator Captain’s Crux, with an Imperial Fist distracting the Warmaster long enough for the killing blow to land. He calls it “one of many apocryphal tales,” which I’d guess is close to how the original framed it.
An Imperial Fist. Obviously. I’ve been painting yellow since 5th edition and I’d never come across that version until last year, which tells you how well my archive research has been going. I did go looking for a scan afterwards and ended up somewhere completely different, reading about the Imperial Fists rebuilding the Chapter from scratch in M32…
Follow the claim forward from 1989 and it swells. One captain’s badge becomes every Terminator’s badge. A tale flagged in-universe as apocryphal becomes a line of background repeated in codex after codex until it gets quoted as fact on forums. There’s a chippy near my old flat with “established 1952” painted on the window, and the paint gets redone every few years, and nobody has ever once asked to see the paperwork.
By the time Imperial Armour Volume 4 covers Brother Dayn’s Indomitus suit, the wording has settled into “legend has it that within each crux is bound a tiny fragment of the suit of battle armour worn by the Emperor during the Siege of Terra.” Legend has it. That hedge has been sitting in the text for a long while now.
The silver ones
Right, so. Confession. There’s a second badge, the Crux Argentum, same sigil cast in silver rather than carved in stone, awarded for acts of valour above and beyond. Separate thing. Higher honour. I painted my Terminators’ Cruces silver. All of them. For about four years.
I thought it was a metallic detail that looked good against yellow. It does look good against yellow. It also meant every one of my big lads was walking round the table wearing a decoration for conspicuous gallantry, which Pete pointed out at the garage one evening in the flattest possible voice while I was still unpacking. He’d known for ages. He’d just been waiting, the way he does. I stripped them and redid them in Codex Grey with a Badab Black wash, and honestly the grey ones look worse, and I’ve stuck with grey anyway.

Calque logs a third form as well, more angular and cubiform, which marks a brother who has completed the Terminator training rather than one who has done something heroic while wearing the plate. So that’s three versions of one sigil, all worn on the same shoulder, all meaning different things, and the whole system is communicated through material and geometry. I’d take a codex page that laid the three of them out side by side with captions. I’ve never seen one.
Anyway.
The Magos who couldn’t find the source
White Dwarf #491, August 2023, runs a long in-universe treatise on Terminator armour written by a Magos Munitoralis called Sydorgeia Calque. It’s framed as a survey. She’s gone round interviewing Space Marines, examining suits, cross-referencing the Cibrene Archives on Mars, and it’s one of my favourite things GW has published in the last few years.
Her line on the badge goes like this. “Upon one shoulder plate of every suit of Terminator armour I have seen… is the Crux Terminatus. This sigil’s origins are unclear even to my investigations, but it appears near unchanged across suits from one millennium to the next.”
Origins unclear. A senior Mechanicus adept with archive access goes looking into the most famous relic claim in the Adeptus Astartes, and what she brings back is that the design has held its shape across a thousand years. The Emperor, the decree, the melted plate: all of it sits outside what she can source.
Now, I can argue myself out of this. She’s one character, the piece is written as a partial account, and unreliable narration is baked into everything the Imperium writes down about itself. Calque failing to find the story doesn’t unwrite it, and decades of older background still say what they say. GW has never retracted anything, because GW never retracts anything. That’s the honest counter-argument and I don’t think it’s stupid.
An author choosing to write an expert who can’t find the source is still a choice, though. She could have found it easily. There was room in the article.
The suits themselves
The same issue is blunt about how few suits exist. Most Chapters hold very few, and Calque reckons it’s likely some hold none at all. The Dark Angels are the outlier, with enough that “some estimate the entirety of their 1st Company could take to battle so armoured,” and the Salamanders have quietly accumulated a large number through their forge world ties, which she flags as unexplained. Imperial Armour Volume 4 puts the Deathwing at around a hundred functioning suits.
Meanwhile the Chaos side of the supply problem is funnier, since the Traitor Legions have been running on a fixed stock of pre-Heresy plate for ten millennia with no forge world willing to build them more. The patterns that predate Indomitus are rarer again, and the Custodes went and solved the mobility problem outright, because of course they did. My local store still had last year’s Crux Terminatus battleforce sitting shrink-wrapped on the top shelf when I went in for paint in August, which is a lot of First Company veterans going unclaimed for a box named after the badge.

There’s a bit in the #491 article I keep coming back to. A Space Wolf is telling a young warrior about Ranulf of the Wolf Guard, who was enormous, and who fell on a mound of dead Orks. His battleplate is in the Hall of Heroes. The Iron Priests repaired the thousand death blows the Orks needed to bring him down, and the old Wolf’s closing line is that if anyone ever refashions the suit to fit a normal-sized brother, “there will be enough armour to equip three warriors more.”
So one Chapter is sitting on a suit big enough to make three, keeping it whole because of who wore it, while other Chapters have none at all. That’s a stranger fact about the Imperium than anything in the relic story, and nobody in the article treats it as worth remarking on.