What happenned to Angron and Corvax between the scattering of the primarch and their discoveries?

Question

I was reading the warhammer 40k wiki page of the primarch when I saw this table:

Legion Number	Primarch	Legion	Name World of Rediscovery	Date of Rediscovery
XVIth	Horus	Luna Wolves	Cthonia	801.M30
VIth	Leman Russ	Space Wolves	Fenris	819.M30
IInd	RECORDS REDACTED	RECORDS REDACTED	RECORDS REDACTED	RECORDS REDACTED
Xth	Ferrus Manus	Iron Hands	Medusa	824.M30
IIIrd	Fulgrim	Emperor's Children	Chemos	830.M30
XVIIIth	Vulkan	Salamanders	Nocturne	832.M30
VIIth	Rogal Dorn	Imperial Fists	Inwit	835.M30
XIIIth	Roboute Guilliman	Ultramarines	Macragge	837.M30
XVth	Magnus the Red	Thousand Sons	Prospero	840.M30
IXth	Sanguinius	Blood Angels	Baal	843.M30
Ist	Lion El'Jonson	Dark Angels	Caliban	846.M30
IVth	Perturabo	Iron Warriors	Olympia	849.M30
XIVth	Mortarion	Death Guard	Barbarus	854.M30
XVIIth	Lorgar	Word Bearers	Colchis	857.M30
Vth	Jaghatai Khan	White Scars	Mundus Planus	865.M30
VIIIth	Konrad Curze	Night Lords	Nostramo	896.M30
XIIth	Angron	World Eaters	Nuceria	899.M30
XIXth	Corvus Corax	Raven Guard	Deliverance	922.M30
XIth	RECORDS REDACTED	RECORDS REDACTED	RECORDS REDACTED	RECORDS REDACTED
XXth	Alpharius Omegon	Alpha Legion	Unknown	981.M30

I was wondering what some primarch did during this time. In particular Angron and Corvax who were found particulary late into the crusade but were not in charge of the planets they were dropped off. Was Angron a gladiator for almost a hundred years? Did Corvax stayed in prison for all of this time? Or did the warp dropped him way later than the others?

Answer 1

Per Deliverance Lost and some other sources, Corvus was raised on the moon Deliverance then leading a rebellion against the enslaver technocrats on the planet below. He managed to wrap up that situation via dropping things (either rocks or nukes I can't remember) out of the sky onto the technocrats' cities about the same time the Emperor found him.

For Angron (primarily in After Desh'ea but from other sources like his primarch book etc) he was a gladiator for decades and then led a gladiator rebellion against the "High Rider" civilzation that enslaved him. However unlike Corax his rebellion wasn't successful, with Big E teleporting Angron away from his army just before their disastrous final battle against the High Riders that led to his army's annihilation. Which is the root cause of Angron's.... dislike... of the Emperor and the Imperium.

Based on the (very sketchy) timeline you can piece together from Corax arriving on-planet and Big E arriving only a decade or so passed. So presumably Corax arrived "late" compared to other primarchs found earlier. The same thing might be true of Angron though he seems to have spent a lot longer as a gladiator and fighting his slave rebellion than Corax did as a prisoner/rebel leader.