Changes

|The Lucien Mechanicum founds an outpost on [[Mezoa]].

|[[The Horus Heresy Book Four - Conquest]] pg. 66

|-

|ca. 570-750.M30

|The Siege of Samerkend in the [[Unification Wars]] sees 10,000 [[First Legion]] [[Astartes]] appear en mass publicly for the first time

|[[The Horus Heresy Book Nine]] pg.84

|-

|ca. 675.M30

|style=background:#4F4F4F align=center|'''Event'''

|style=background:#4F4F4F align=center|'''Source'''

|-

|ca. 745.M30

|[[Descent of Angels (Novel)|Descent of Angels]] Chapter Eighteen <!-- 200 years before Sarosh -->

|-

|[[Fall of the Eldar]] - The [[Eye of Terror]] erupts in the heart of the [[eldar]] empire as [[Slaanesh]] is born. She Who Thirsts tears billion of eldar souls from their bodies. Only the [[Exodite]] and [[craftworld]]s far from the empire and [[webway]] domains such as [[Commoragh]] survive. The eruption of psychic energy blows away the warp storms that had made interstellar travel impossible for thousands of years.

|[[Codex: Eldar (4th Edition)]] pgs. 4-5; [[Codex: Dark Eldar (5th Edition)]] pg. 20; [[The First Heretic (Novel)|The First Heretic]] Chapter Seventeen; [[The Horus Heresy Book Two - Massacre]] pg. 14

|-

|

|An [[Eldar]] [[craftworld]] crashes on [[Typhon Primaris]]. The jungle eventually claims it and it will be lost for ten thousand years.

|[[Warhammer 40,000: Dawn of War II - Retribution]]

|-

|ca. M30

|-

|792.M30

|-

|rowspan=2|798.M30<!-- Date given in Imperial Knights -->

|[[Horus Rising (Novel)|Horus Rising]] Chapter One; [[Warhammer 40,000 6th Edition Rulebook]] pg. 168; [[Codex: Imperial Knights (6th Edition)]]; [[Magnus the Red: Master of Prospero (Novel)]] Chapter 1

|-

|-

|

|[[Molorian Revolt]]

|[[The Horus Heresy Book Seven - Inferno]] pg. 92

|-

|rowspan=2|803.M30

|The Nephritil and Ayurnas wipe out the Mohindas 11th.

|[[Mark of Calth (Anthology)#Unmarked|Mark of Calth: Unmarked]] <!-- 6th year of GC -->

|-

|

|The [[Primarch]]s are rediscovered and united with their Legions. Hundreds of thousands of human worlds are reclaimed under the [[Pax Imperialis]].

|[[Warhammer 40,000 6th Edition Rulebook]] pg. 168

|-

|<!-- 10 years after Lion's arrival -->

|[[Siege of Reillis]] - <!-- At this time the Emperor have rediscovered only Horus-->

| [[Index Astartes IV]] — ''Sons of Horus''

|-

| ca. 810-835.M30 <!-- The novel Wolfsbane (chapter 9) indicates that this event ocurred when the Emperor have rediscovered only Horus, Leman Russ and Ferrus Manus-->

|[[Mezoa]] becomes a [[Forge World]] of the [[Adeptus Mechanicus]].

|[[The Horus Heresy Book Four - Conquest]] pg. 66

|-

|823.M30

|[[Rogue trader]] Vaspperly Elgin makes contact with the pre-industrial remnant human inhabitants of [[Lethe]].

|''Ibid.'' pg. 73

|-

|ca. 829.M30

|The [[Emperor's Children|III Legion]]'s [[gene-seed]] reserves fail to arrive at the vaults on [[Luna]] and an artificial pathogen obliterates several gene-seed vaults on [[Terra]], sealing the fate of the III Legion.

|[[Index Astartes]]: [[Emperor's Children]]; [[The Horus Heresy Book One - Betrayal]] pg. 104; [[The Horus Heresy Book Three - Extermination]] pg. 80

|-

|<!-- Shortly after the III Legion gene-seed loss. -->

|Anomalous Legiones Astartes activity is first reported. The actions of unidentified Astartes is attributed to a "Ghost Legion."

|[[The Horus Heresy Book Three - Extermination]] pg. 81

|-

|833.M30

|'''Recruitment of Rogal Dorn''' - The [[Emperor of Mankind|Emperor]] comes to [[Inwit]] and recruits [[Rogal Dorn]] to lead the [[Imperial Fists]]. Dorn is the seventh lost son found.

|[[Index Astartes]]: [[Imperial Fists]]; [[The Dark King and The Lightning Tower (Audio Book)|The Lightning Tower]]; [[The Horus Heresy Book Three - Extermination]] pg. 60; [[Praetorian of Dorn (Novel)|Praetorian of Dorn]] ''Gift of the Father''

|-

|

|[[Descent of Angels (Novel)|Descent of Angels]] Prologue, Book Two, Book Three

|-

|'''Recruitment of Roboute Guilliman''' - The [[Emperor]] comes to [[Macragge]] to meet [[Roboute Guilliman]]. Recognizing him as [[Primarch|his son]], the Emperor brings Guilliman to lead the XIII Legion. The Legion adopts the trappings of Guilliman's culture and becomes the [[Ultramarines]].

|-

|rowspan=2|840.M30

|[[The Horus Heresy Book Eight - Malevolence]] pgs. 119-121

|-

|-

|The 4th Expeditionary Fleet discovers [[Sarosh]]. Harlad Furst is appointed [[Imperial governor]], but the planet's impenetrable bureaucracy prevents any action toward Compliance for over a year. The Saroshi try to destroy ''[[Invincible Reason]]'' with an atomic bomb, but are defeated.

|[[Descent of Angels (Novel)|Descent of Angels]] Book Four; [[The Horus Heresy Book Eight - Malevolence]] pg. 12

|-

|849.M30 <!-- late 840's; barely four years before Morningstar -->

|The [[Thousand Sons]] and [[Iron Warriors]] respond to evacuate the population of [[Morningstar (Planet)|Morningstar]] while the planet suffers catastrophic geomagnetic upheavals. No native of the planet survives its destruction.

|[[Magnus the Red: Master of Prospero (Novel)]]

|-

|856.M30

|[[Purging of Arachiana]] - [[Lorgar]] leads the [[Word Bearers]] to destroy the Cult of the Iconoclast on the planet [[Arachnia]]. The sect worships "The One True God," who is described in ways similar to the Emperor. Lorgar incorporates elements of the Cult's dogma into early versions of the [[Book of Lorgar]].

|[[The Horus Heresy Book Eight - Malevolence]] pg. 12

|-

|ca. 860.M30 <!-- "Korchin ... had been the language of the Legion for the hundred and twenty years since the Master of Mankind had made himself known to us." Jaghatai named among Primarchs at Molech compliance, so this must pre-date that event. -->

|[[Ork]]s invade [[Rennimar]] shortly after the [[Imperial Fists]] bring the world to Compliance.

|[[Praetorian of Dorn (Novel)|Praetorian of Dorn]] ''Lord of Conquest''

|-

|866.M30

|[[Emancipation of Drune]]

|[[The Horus Heresy Book Eight]] pgs. 150–152

|-

|rowspan=2|ca. 890.M30 <!-- Other side of thirty-year span beginning Farinatus -10y -->

|'''Discovery of Grail''' - [[Rogue trader]] Corthona Van Der Veld discovers the dead world that she names [[Grail]].

|[[The Horus Heresy Book Four - Conquest]] pg. 71

|-

|897.M30

|The [[World Eaters|War Hounds]] encounter the Osirian Psybrids while battling the [[Ork]]s of the Glortian Empire near Eurydice Terminal. [[Roboute Guilliman]] receives astrotelepathic information and moves to reinforce the War Hounds and wipe out the Psybrids.

|[[The Horus Heresy Book Five - Tempest]] pg. 97

|}

|The [[Word Bearers]] bring Forty-Seven Ten (Khur) to Compliance. They eventually turn the planetary capital [[Monarchia]] into a temple city dedicated to worship of the Emperor.

|[[The First Heretic (Novel)|The First Heretic]] Chapter One

|-

|921.M30

|[[Battle of Keylek]] - The [[Luna Wolves]] [[Battle of Keylek|exterminate]] the [[keylekid]] [[xenos]].

|[[Horus Rising (Novel)|Horus Rising]] Part One Chapter Nine <!-- "This was eighty years ago" -->

|-

|926.M30

|[[The Horus Heresy Book Four - Conquest]] pg. 72

|-

|[[Cryptosi Purgation]].

|[[The Horus Heresy Book Three - Extermination]] pg. 94

|Mark II Legiones Astartes [[power armour]] is considered largely obsolete by this time.

|''Ibid.''

|-

|933.M30

|<!-- "towards the end of the Great Crusade" -->

|A [[Luna Wolves]] fleet led by [[Horus]] responds to a distress call from a scout ship lured into a minefield. Horus discovers that the attackers have boarded the ship and comes face to face with the intruders' leader: the last [[Primarch]] [[Alpharius]]. Alpharius remains at Horus's side for several months before journeying to [[Terra]] and meeting the [[Emperor of Mankind]].

|[[Index Astartes]]: [[Alpha Legion]]

|-