This archive tracks four layers. A record present in 1 of them (HH) is silent in the rest, and says so.
The Horus HeresyM30–M31
contested
Forge world torn by a Mechanicum civil war
A forge world of the Imperium that split when the Heresy reached it, the loyalists under Magos Heironymax Veltarae outnumbered by the traitor faction of Bellonitrix, until a Dark Angels fleet led by the Invincible Reason arrived seeking repairs and Lion El'Jonson agreed to fight for the loyalists (Dreadwing). Canon gives it no segmentum, sector or system, and says nothing of what it looks like beyond what a forge world is.
Age of the ImperiumM32–M40
[RECORD LOST]
No record for this location in Age of the Imperium.
The 41st Millenniumpre-Rift
[RECORD LOST]
No record for this location in The 41st Millennium.
Era Indomituspost-Rift
[RECORD LOST]
No record for this location in Era Indomitus.
Position
Map frame: 769.6, 865.3 in the archive's 0–1000 disk space (core at 500, 500).
Distance from the core: 454 units ≈ 48.3k light years, south-east of the galactic core.
Height above the disk plane: -10.5 units — invented thin-disk jitter, deterministic per record. No published source gives any location a z coordinate.
System: Thagria System
Books set here
1 title in the reading tracker touches this record. Titles link out to the tracker.
Every fact in this record, and where it came from. Editorial derivations say so.
identityhigh
wh40k.lexicanum.com/wiki/Thagria (read directly in a browser on 2026-10-02): 'Thagria is a Forge World of the Imperium'; the civil war between Magos Heironymax Veltarae's loyalists and Bellonitrix's traitors; 'a Dark Angels fleet led by the Invincible Reason itself arrived seeking repairs. Lion El'Jonson agreed to aid the loyalists against the traitors, subsequently crushing them with the Dreadwing' (sole source: Dreadwing (Novella)). NAME-COLLISION CHECK: no index record or alias uses the name, and Lexicanum has one Thagria.
segmentumhigh
null: the Lexicanum infobox leaves Segmentum, Sector, Subsector and System blank and files the page under 'Segmentum Unknown'. No permitted source gives a neighbour or a route.
gposlow
inferred: the world is NAMED but canon never locates it, so the record claims no segmentum and sits on the unsurveyed rim at the generator's rim_xy('thagria') = [769.6, 865.3] (the function in build_locations.py evaluated on its own, reproducing charchera [936.8, 514.1] and vorganthian [896.8, 713.6]; the script was not run). The position carries no information: it is NOT a claim that Thagria lies south-east of anything, nor near Barbarus or Chemos. Z -10.5 is the zPolicy value (compute-z.mjs thagria 769.6 865.3). UPGRADE CANDIDATE when a source fixes its sector.
classmedium
'forge': Lexicanum's infobox Class is Forge World, and the only description is of a Mechanicum world at war with itself; no terrain, climate or colour words are published. A forge world is what this palette paints (Mars), so the tag and the picture agree here, unlike the Death World tag Step 5a2 warns about. Medium because nothing describes the surface itself.
erashigh
hh only, the era of the one book that names it. Allegiance 'contested': loyalist and traitor Mechanicum factions at war (Lexicanum Thagria). The outcome (the Dreadwing crushing the traitors) is a plot beat kept out of the status and summary; the record does not claim the world's later fate.
systemIdmedium
editorial: 'thagria', the world's own name; no system is published.
no-system-surveyhigh
NO systems/thagria.json is authored: it is a VISITED setting of Dreadwing, not its primary, and canon names no star, body or count for it. The synthesiser draws it from its class and seed (hashId('thagria') % 97 = 80).