Board Thread:Warhammer 40k General Discussion/@comment-6078851-20130130174042/@comment-4264245-20130218195648

Well, that Gravius (Salamander sitting guy) thing was simply too much, but Space Marines normally last around 300-500 years depending on their geneseed quality. Leman Russ' and Sanguinius' were the most powerful ones, so the Great Wolf is around 600yo and his Wolf Guard could be 800yo, Dante has been in charge of the BA 1400 years and Cleutin was a Veteran Sergeant when he arrived as a Scout. This is a topic not usually touched on novels or fluff because, man, it's not heroic to talk about a superwarrior devolving into a sack of wrinkles in a few years after so many deeds. That should usually end with a "final battle" to "die fighting" instead of in bed, very knightly and so.

About Primarchs immortality...I sincerely doubt it was like that. As The Outcast Dead shows us, the Emperor made things for an end, and designed them to last for as long as they were supposed to be needed. Thunder Warriors lived a few years, then died and were quickly replaced, so when the Unification was done, they simply were never replaced again. Astartes were made for the Great Crusade and then to keep protecting the conquered realms, so they lasted longer and had a means to keep reproducing themselves (progenoid glands). And Primarchs were the generals to lead the conquests - what should be done of them in the peaceful, bureaucratic empire that would follow? Astartes are capable to direct campaigns on their own, why should we keep such dangerous beings that live to make war? So maybe the original plan (insinuated by Arik Taranis) was to let them suddenly start to age and finally die after having built an stable Imperium of Man. Then came the Heresy, and the Eternal War begun. Imo, the few remaining Primarchs decided to leave their Chapters with hope they'd one day return, mostly after completing some quest (like the Salamanders) and meanwhile hid and slept in stasis if they were not battling inside the Warp. What do you think?