White Dwarf #469 has a line about MkIV armour that I keep going back to. With the benefit of hindsight, it says, the bulk of Maximus armour stocks “had been diverted to those Legions the Warmaster anticipated would follow him into treachery.” Not stolen. Diverted. Diverted implies paperwork, a signature, a shipping manifest somebody in the Mechanicum filed and then forgot about.
MkIV Maximus armour is the mark whose distribution history keeps surfacing in the lore itself, and it’s on my mind because the MkIV Tactical Squad and Assault Squad went up for pre-order on Saturday, together with a Combi-weapons and Shotguns upgrade set containing 40 combi-weapons and 10 Astartes shotguns. That’s more guns than any reasonable person needs and I want two of them.
The Mechanicum designed it late. Index Astartes Apocrypha puts the programme roughly two centuries into the Great Crusade, when the MkII and MkIII suits coming off the Martian forges were wearing out faster than the Legions could replace them, and a lot of Marines had shifted from campaigning to garrison duty. The structural change was giving up the separate abutting plates of the older marks in favour of large inflexible casings with the flexible joints built into them. Marginally less mobile. Much easier to produce and repair. Better armouring on the power cables meant the main chest and arm supply could be moved to the outside of the suit, which is why MkIV has that ribbed cabling running across the plastron. The helmet moves with the wearer’s head, too. In every mark before it the helmet was fixed in place and the Marine’s head just rotated around inside it, which I’ve never been able to stop thinking about since I read it.
The requisition
So the good stuff went to the Sons of Horus and the Emperor’s Children. White Dwarf #469 says both had been issued vast stockpiles in the run-up to Isstvan III, with the Word Bearers, Night Lords and Alpha Legion getting theirs in varying quantities. Warhammer Community made the same point in a footnote back in June, on an article about kitbashing Despoiler Squads of all things: the Warmaster managed to requisition a lot of it before he revealed his heresy.
Which is a very dry way to describe a coup. Horus was Warmaster, and Warmaster is an administrative post as much as a military one. Administrative posts come with sign-off authority over what gets shipped where. Every office I’ve worked in has had somebody who knew the procurement calendar well enough to have the good chairs and the new monitors sitting in their department before anyone else had heard there was a budget. Horus had that authority over the ceramite output of Mars for years before anyone thought to audit it.
I do want to complicate this, because the same White Dwarf undercuts it a couple of pages later. In the sidebar on armour through the ages, it notes that the Ultramarines, the most numerous Legion in the records of the day, “managed to procure it in great numbers too.” My reading is that the XIII was simply so enormous that even a rigged distribution left them sitting on a mountain of the stuff. Though I’ve argued the other way before, that the diversion just had hard limits and Guilliman’s quartermasters were as sharp as anybody’s, and I might well end up back there.
At the moment the Heresy broke out, MkIV was the single most common pattern in service across the entire Legiones Astartes. Every Legion had some, and the ones who turned generally had more of it.
Why MkIV Maximus armour was supposed to be the last one
The design brief is the part that actually gets me. Index Astartes Apocrypha states it flatly: MkIV was intended to be the ultimate and final type of Space Marine armour, able to offer the best protection across every condition the Legions might meet. Mars turned its factories over to it and the Legions began re-equipping wholesale, with the intention of finishing the job and never designing another suit.
That’s an extraordinary thing to believe about a piece of military hardware, and it tells you what the late Crusade felt like from the inside. The galaxy was being conquered on schedule. Newly compliant worlds were coughing up archeotech faster than the Mechanicum could catalogue it. Somebody in a Martian design bureau looked at all that and concluded that armour development was finished as a discipline. The suit got a Suspensor layer to shield the wearer from extreme pressure and gravity, on the assumption it would need to work everywhere, forever.
General issue was about half done when Horus turned, and the supply chain fell over almost immediately. The MkIV used new specialised materials that couldn’t be sourced locally, and because it was brand new nobody had stockpiled spares, so suits were going out of service from damage a Techmarine could have patched on a MkIII in an afternoon. Legion armourers hadn’t finished learning the thing. Apocrypha says many of them couldn’t properly maintain it, let alone duplicate it, which had been the whole point of the design. Loyalist formations that never received their allocation ended up fighting in older marks against brothers wearing the newest plate in the Imperium.
So they built MkV. Overnight, basically. Older cabling because the light MkIV stuff had run out, and the old cables were too bulky to fit under the chest plate so they just ran them on the outside, which made a permanent weak spot everyone then covered with improvised armour. Studs everywhere. Molecular bonding studs holding an extra skin plate over inferior ceramite. Heavier, so more power draw, so you either turned the output up and cooked or left it down and moved slower. Helmet borrowed off the Terminator prototype line. It’s a bodge, and it worked, and they shipped tons of it, and Horus ended up scavenging it off corpses once his own supply got tight.
The armour marks track the material condition of the war fairly precisely. The traitors left Terra well equipped, and by the closing years both sides were fighting in whatever ceramite they could bolt together. The Chaos Terminators still walking around in 40K are the long tail of exactly that problem.
The Calth box in my loft
I bought Betrayal at Calth in 2015 for the MkIV marines. Thirty basic Legionaries, and I barely looked at the Contemptor or the Cataphractii on the way past. I had a plan to do them as Imperial Fists, I got fourteen painted to a standard I was happy with, and the other sixteen are still on sprue in a box in the loft. Eleven years, which is longer than my kid has been alive. Pete has painted three entire armies in that time and he keeps asking whether I want to “do something” with the Calth stuff, by which he means give it to him.
Worse: for about two years after that I was the guy at my local store correcting people on which Legion wore which mark, working entirely off one White Dwarf sidebar and a Forge World book I’d skimmed in the shop rather than bought. I was confidently wrong about MkV for an embarrassingly long time. I told at least one person it was purely field improvisation, which is only half right, since there was a production version made in Legion forges to a semi-standard pattern with parts borrowed from early MkVI.
The Thousand Sons thing is a separate rabbit hole I’m not going down properly here. Short version: they seem to have adopted Maximus late in the Heresy, nobody has explained why, and the Rubric Marines are almost all wearing ornamented MkIV, so the mark commissioned as the crowning achievement of Imperial armoursmithing is now most famous as a set of coffins full of dust…
What you actually get in the box
The Tactical Squad is 20 miniatures with upgrade parts to build one or two Sergeants. The Assault Squad is 10 with bolt pistols, chainswords and jump packs, plus 10 power lances so you can run them as Veteran Assault Marines. The Combi-weapons and Shotguns set has 10 each of combi-flamer, combi-plasma, combi-melta and combi-volkite, 10 Astartes shotguns, two one-handed versions of each so they’ll fit a MkIII Breacher holding a boarding shield, and 60 pouches, magazines and grenades. That last kit works with the MkII, MkIII, MkIV and MkVI Tactical Squads and the MkIII Breacher box.
For anyone starting a Heresy force, MkIV is the sensible mark to commit to. It was the most common pattern in service across the whole Legiones Astartes in 30,000, which makes it defensible for any army you feel like building, and it happens to look like the thing most people already picture when they hear the word Legion. MkIII reads as boarding kit and MkVI belongs to the back half of the war, so both of those carry implied backstory you might not want yet. If you want the newer, sleeker end of Astartes wargear instead, that’s a whole different argument I’ve had about Phobos plate.
Whether GW needed to sell this to us in quite so many separate boxes is another conversation. The Maximus Battle Group went up last month with 20 Tactical and 10 Assault Legionaries, a Sicaran and a Contemptor in one package, and now the same infantry are available individually, which is fine and normal and also means a full 20-man squad with combi-weapons has crept somewhere north of what I’d have paid for an entire army in 5th edition. There’s still a shrink-wrapped Burning of Prospero sitting on the shelf at my local store, MkIII marines and all, at whatever price it was marked at years ago, and I look at it every time I go in.
I’ll probably buy the combi-weapon sprues anyway. I have sixteen unpainted Legionaries who need something to hold.
