Astartes recruitment ages

Apologies if the formatting is a bit wonky. I had some issues trying to post this earlier.

The maximum age at which people can be turned into space marines seems to be the subject of a lot of debate, so I figured I’d chime in and write a short post about what I’ve found after a bit of searching. According to this post by Laurie Golding (used to work for GW/BL as an editor/writer, especially for the Horus heresy series) it seems that current Astartes methods of generally recruiting only younger adolescent candidates is not strictly necessary, and that in the great crusade/heresy eras adults could be, and commonly were, implanted with gene-seed and turned into marines. https://www.tapatalk.com/groups/thefirstexpedition/viewtopic.php?p=22136388#p22136388 The World Eaters would put gene-seed into basically anyone they thought would survive the process, and the Wolves made Russ’s companions into full astartes with more surviving than projected, and (my assumption is that) they must have been men ranging from 20-60’s based on Fenrisian/Viking culture and them being the best warriors and his personal guard as King. There’s also a bit more info in this thread https://www.tapatalk.com/groups/thefirstexpedition/viewtopic.php?p=22136542#p22136542 Now, if that was a smart idea or not is unclear, as that may have been one of the reasons for stuff like the warrior lodges popping up and so many marines being willing to go traitor. A similar concern is raised in the first Forge World Horus Heresy book, when talking about Grabiya’s Theorum.

My personal take on all of it is that Astartes can technically be made at almost any age, but the further away you get from the body still growing (mid 20’s or so) the less the chance for success. Modern militaries recruit people well older than that, but elite units tend to have an age limit of upper 20’s/lower 30’s so personally I like that for Astartes as well. People like Kor Phaeron who were made into pseudo-Astartes likely had that done due to them being much older (60’s-70’s or so), so the risk of them dying was much higher and (using Kor as an example) they were valued by their primarchs so much so that the risk of them dying was unacceptable. Now, in “modern” 40k times I can see why they would take younger recruits (better indoctrination, more grimdark, etc.) but I do like the idea that in the crusade and Heresy recruitment worked a bit more like an actual elite military unit. Also, with all of the stories of aspirants doing crazy feats in tribal wars, etc. it would make sense that quite a few are a bit older, as most 8 year olds wouldn’t be able to win a fight against a fully grown feral world tribesman.

Tl;dr: Space Marines can technically be made from men of almost any age, but gene-seed is valuable and the older one gets, the lower the chance of success. Most modern chapters recruit younger because of the lower risk and fear of repeating mistakes that led to the Heresy, but during the Crusade and Heresy adults were commonly made into full Astartes.