Average life expectancy of a battle company space marine?

[Lord Kallozar]

What is the average life expectancy of a space marine? I don’t mean how long do they live if they survived through battles, I do mean what is the expectancy of a battle ready astartes in action?

[slitth]

I am going to assume that you are talking about lore life expectancy.

 

That in is self is a hard question. Losing one battle brother is a heavy blow in the lore, so I would expect that a certified astartes would live a long time.

I would say 100 years is the average life expectancy.

[Lucien Eilam]

300-400 years has typically been said to be the most any could expect to live before dying in battle. Multiple service studs to mark 50 or 100 years are common.

 

Dante has known “1,100 years” of war at the close of M41.

 

Sigismund “survived for a thousand years because he refused to die. He hated us too much to sleep in his grave with his duty undone.”

 

The known record in realspace is Gravius, a Salamander who sat on a throne in a wrecked ship continuously after fleeing Isstvan V until M41, although he wasn't much use for anything at that point.

 

In the warp, where time moves strangely, Marines can experience eternities.

[Slan Drakkos]

The average life expectancy is somewhere between 300-400 years old.

 

Right now, Dante is the oldest living (non dreadnought/non chaos)space marine. He's somewhere close to about 2000 years old.

 

Gravius of the Salamanders is the best known example of a space marines immortality. He lived for close to 10,000 years.

[Lord Kallozar]

Cheers guys. On a relatable note, how long would it take then for a chapter to go through a full cycle of new recruits?

[apologist]

My thoughts, and reasoning behind my conclusions below, are detailed here, but in summary:

 

There are between twenty and fifty Neophytes between ten and fourteen years old, who are not part of the 1,000 marine limit.

 

The Scouts of the Tenth company are between twelve and twenty-one years old.

 

A Battle Brother in a Reserve Company will be between eighteen and fifty-five years old.

 

A Battle Brother in a Battle Company will be between thirty-four and eighty-one years old, with members exceptionally reaching one-hundred-and-fifty years or more.

 

A Veteran of the First Company will be between sixty-five and two-hundred-and-thirty-five years old, with members exceptionally reaching three-hundred years old

 

An Officer will be between thirty-five and three-hundred years old.

 

These dates are based on casualties sustained; but the direct answer to your question was explicitly given in the original Codex: Ultramarines - Marines live to three centuries, after which they show signs of extreme old age. [...] and went on to say that marines who began to slow were given non-combat duties.

 

+++

In answer to your second question, what do you mean by ‘full cycle’?

[Master Commander Ajax]

After the Babdab War the secessionist Chapters were sentenced to a one hundred year penance crusade during which time they were forbidden to recruit new members. The Lamenters were reckoned to number around 300 Marines at the time with the Mantis Warriors being similarly depleted. A crusade is an active military campaign so it's not much of a stretch to imagine they would be involved in numerous actions. The survival of these Chapters seemed unlikely but importantly it was not out of the question. This would give you a rough idea as to average life expectancy. 

 

Of course, there are numerous other factors that would influence it including time period and location. Similarly, an event which wiped out the majority of a Chapter (such as the Blood Angels failed assault on the Space Hulk Sin of Damnation) would skew the figure significantly.

 

 

So yeah, I guess it would vary greatly but a ballpark figure for an Astartes on fairly active duty would be around a hundred years (by my reckoning).

[Marshal Rohr]

My thoughts, and reasoning behind my conclusions below, are detailed here, but in summary:

 

There are between twenty and fifty Neophytes between ten and fourteen years old, who are not part of the 1,000 marine limit.

 

The Scouts of the Tenth company are between twelve and twenty-one years old.

 

A Battle Brother in a Reserve Company will be between eighteen and fifty-five years old.

 

A Battle Brother in a Battle Company will be between thirty-four and eighty-one years old, with members exceptionally reaching one-hundred-and-fifty years or more.

 

A Veteran of the First Company will be between sixty-five and two-hundred-and-thirty-five years old, with members exceptionally reaching three-hundred years old

 

An Officer will be between thirty-five and three-hundred years old.

 

These dates are based on casualties sustained; but the direct answer to your question was explicitly given in the original Codex: Ultramarines - Marines live to three centuries, after which they show signs of extreme old age. [...] and went on to say that marines who began to slow were given non-combat duties.

 

+++

In answer to your second question, what do you mean by ‘full cycle’?

This was a really solid explanation! I definitely agree.

[Semper Fortis]

Impressive article, Apologist.

 

My one issue would be this: Wouldn't the average life expectancy of a marine of a given chapter depend greatly upon the fighting style and willingness of its leadership to sacrifice warriors?

[Red_Shift]

Impressive article, Apologist.

My one issue would be this: Wouldn't the average life expectancy of a marine of a given chapter depend greatly upon the fighting style and willingness of its leadership to sacrifice warriors?

IIRC gw explained away their habit of killing off large numbers of imperial fists in the fluff (them being used ala Worf whenever a foe needed to be shown to be deadly dangerous) by saying that they maintained a much larger scout recruiting pool. So the aspirants that Apologist mentions that don't count towards the total could be a much higher number in chapters with a high attrition rate

 

Also, great post, Apologist!

[Cpt_Reaper]

Also of note is Barabas Dantioch of the Iron Warriors who was aged roughly 3000 years by the temporal effects of the Hrud. He suffered arthritis and other afflictions of extreme age, despite his modified physiology. Other Iron Warriors were said to have their Astartes organs fail.

 

Of course this is 30k era where things may have been done differently.

[apologist]

Thanks, fraters.

 

My one issue would be this: Wouldn't the average life expectancy of a marine of a given chapter depend greatly upon the fighting style and willingness of its leadership to sacrifice warriors?

 

Yes, almost certainly. I make the note that the article looks at a typical (i.e. Codex) Chapter, but it's worth making it explicit that every Chapter is going to have its own way of operating, which will affect the numbers I've mooted. A particularly disastrous campaign, or a craft lost in the warp, for example, will have a huge impact on average life expectancy.

 

Coming back to Lord Kallozar's initial question, 'what is the expectancy of a battle ready astartes in action?' I'm not sure we really addressed the 'in action' part.

 

I reckoned that marines suffer six permanent casualties per Army (i.e. 250 marines) per campaign (which I estimated at one year long on average, before the Guard arrive to take over), which gives you, on average, one permanent marine casualty – death or being rendered permanently non-combat capable – every two months.

 

That allows you to work out the life expectancy for a typical marine in a typical Chapter on a typical campaign as 365/60 x 250 (days in a year divided by the number of days in two months, mulitplied by the number of marines involved) which works out at 1521 days (just over four years) – rather more than the fifteen hours of a guardsman! 

[Lucifer216]

I think one of the biggest issues with the sort of ages that seem to get bandied around for 'typical' space marines is the conflict between heroism and survival it creates and the sort of circumstances where space marines are required. The galaxy is filled with creatures and warriors that are approximately equal to space marines (the obvious example being their traitor counterparts). While putting elite forces into situations where they're facing their counterparts in roughly equal strength is to be avoided, it must happen from time to time, particularly when defending a world against xenos/chaos invasion or when trying to destroy an enemy's command structure only to find that they have elite bodyguards to prevent this from happening. 

 

In either situation, casualty rates would start to resemble those between conventional forces and the space marines' ability to heal injuries becomes null and void if their opponents win the field and start shivving all the injured. 

 

There's also the problem of space battles/titans and superheavies potentially deleting entire squads/companies in big chunks. 

 

The only way I can think of a space marine reaching 300+ life spans would be a combination of long travel times between engagements and never fighting the enemies' elites on anything like equal terms.

[apologist]

I think one of the biggest issues with the sort of ages that seem to get bandied around for 'typical' space marines is the conflict between heroism and survival it creates and the sort of circumstances where space marines are required. The galaxy is filled with creatures and warriors that are approximately equal to space marines (the obvious example being their traitor counterparts). While putting elite forces into situations where they're facing their counterparts in roughly equal strength is to be avoided, it must happen from time to time, particularly when defending a world against xenos/chaos invasion or when trying to destroy an enemy's command structure only to find that they have elite bodyguards to prevent this from happening. 

 

In either situation, casualty rates would start to resemble those between conventional forces and the space marines' ability to heal injuries becomes null and void if their opponents win the field and start shivving all the injured. 

 

There's also the problem of space battles/titans and superheavies potentially deleting entire squads/companies in big chunks. 

 

The only way I can think of a space marine reaching 300+ life spans would be a combination of long travel times between engagements and never fighting the enemies' elites on anything like equal terms.

 

Excellent points there, and they highlight the conflict between the depictions of Space Marines in the background. Some sources have a semi-realistic view (well, at least a nod to realism), stressing that Astartes are only committed to lightning strikes; and that – powerful as they are individually – they are also aware of their value, and retreat if their shock assault fails. The other angle is the Boy's Own feel of them operating like a conventional military force.

 

+ The semi-realistic model +

Taking the first instance (the special operations depiction), we can use modern special forces as an equivalent. Judging from these (hastily-googled) statistics, we see modern special forces have a much lower casualty rate than is typical for military personnel, so when applying the same mitigations I outline in the earlier article, we see that Space Marines are particularly survivable – indeed, all but invincible – if they get to operate on their own terms.

 

I think it's fair to assume that they get to operate on those terms more often than not – such small, nimble groups are hard to pin down on a galactic scale. Indeed, unless that is the case, it's very hard to justify old Space Marines. 

 

However, as Lucifer216 points out, there are plenty of example of Space Marines fighting on equal (or inferior) terms. In this model, we have to assume that when a Chapter is not fighting on its own terms, it is a rare and noteworthy occasion. This makes sense in terms of the stories, and perhaps explains why so many of the stories show so many marines dying. After all, heroic struggle is inherently more dramatic than 'a professional day as usual'.

 

Given that, I think it's fair to allow for Space Marines to live to the ages I suggest – but I would add that this is precisely why I make the following point:

 

 

I'd like to note that it's very easy to start throwing around huge numbers when writing. The temptation to say that Character X 'fought in thousands of campaigns' or 'trained for many centuries', but if you spend a minute or two thinking about that, it quickly becomes incoherent. For this reason, I prefer to be a little more conservative in terms of numbers and time.

 

Even taking that into account, the oldest marines (outside of the exceptional veteran Company) I outline don't exceed 80. Most are 40–50. 

 

+++

On specifics:

There's also the problem of space battles/titans and superheavies potentially deleting entire squads/companies in big chunks. 

In exceptional cases; yes – and I suspect that such battles/events are at the root of most Chapters going extinct. Similarly to the point above about narrative drama, it's harder to write a compelling Boy's Own-style story about a rebuilding Chapter that can't fight.

 

 

The only way I can think of a space marine reaching 300+ life spans would be a combination of long travel times between engagements and never fighting the enemies' elites on anything like equal terms.

 

 

Agreed. For my 'typical' Chapter outline, I suggested that in order for the model to be sustainable, there is a fairly significant period of a few months between engagements. 

[Leonaides]

Travel time in the warp - its not instantaneous after all (though it stretches both ways) - and even maybe travelling back to fortress at the end of one campaign/mission before heading to the next unless they do back-to-back campaigns without a full refit/rearm and repair at a chapter station. Even approaching a new world will take a few days/a week or so to travel in-system before ground deployment of marines...

 

Space battle injuries need not be totally fatal either as if they have managed to get into their armour first, and its not punctured, they should be able to survive for a few weeks/months in sus-an till a later salvage/survivor search can pick them up. Each suit has a locator beacon, all marines are chem-prepped for sus-an prior to void battle for a couple of reasons (better cold survival etc). We dont see the post-battle clean-ups very much, if at all, but they are mentioned/alluded too occasionally.

[Lucifer216]

I guess one other factor that needs to be consider as far as the veterans are concerned is the more than physical nature of space marine prowess.

 

The primarchs' abilities were based for the most part in their connection to the warp than their flesh and blood and as their sons, the same must be true for the Astartes (admittedly to a much lesser extent).

 

This may help to explain veterans' high survival rates – in addition to possessing better equipment, having more experience and possibly calling first dibs on the missions involving overwhelming force, they might be the ones in which the geneseed has conferred more of their demi-god fathers' psychically-granted might than their less fortunate kin. 

[SickSix]

I would think your Average marine, maybe lasts 100 years. Think about the attrition. A chapter will be lucky to have a full 100 man 1st Company. So that is maybe 10% living beyond an average life span. Then you have another 5% as chapter leadership.

 

The average lifespan is probably very close to 75 years.

 

Each chapter probably sees a full attrition cycle around 500 years.

[Trevak Dal]

There was a short story I think by Sara Cawkwell that involved the Red Corsairs fighting Sisters of Battle to capture their leader, and the leader seeing her subordinates dead and dying noted that most of the marines were likely going to recover from their wounds-so that got me to thinking that maybe in the course of a game, which in real time scale would be a couple of minutes-bout a Halo team death match worth of time, you get wounded guys who can be patched up by apothecaries and evacuated to get prosthetics/augmetics and put back in the fight, getting ammo dropped in by local air support or drop pods.

 

It's a tiny slice in a much larger engagement unless you are playing at apocalypse levels, and even then it's a tiny scale of the combat.

 

Regarding company set up, I always thought that say, assault marines were all 8th company but tasked to 3rd company, all devestators were 8th, all scouts 10th with reserves and vehicle crewmen brought in as needed and shuffled around.

[Lord_Caerolion]

The other thing to remember is that Chaplain Cassius is the oldest non-Dreadnought (and non-Primarch) within the Ultramarines, which can be taken as the "baseline" for Astartes, given everything we're told about them, and he's only 440 or so. Given the combat they see, I'd say average life expectancy would be roughly 100-150 or so.

[sarabando]

"oh boy i cant wait to purge in the name of the Emperor as a full battle brother its been a hard 20 years of scout training but i am ready!" *Thunderhawk ramp opens* "Here i g.*blam*"

[Kallas]

"oh boy i cant wait to purge in the name of the Emperor as a full battle brother its been a hard 20 years of scout training but i am ready!" *Thunderhawk ramp opens* "Here i g.*blam*"

I mean, that is accurate considering gameplay

[Lord Kallozar]

So would it be realistic that within a 100 years cycle to have most of a chapter (say roughly 70%) killed off and replenished with newer recruits within that time frame?

[Iron Father Ferrum]

70% sounds high to me. Is takes decades to produce a single battle brother after all.

[Lord Kallozar]

So what kinda figures would be realistic?

[Boldthreat]

This is fascinating stuff.  I must say @Apologist, you have made a solid case here for how standard chapters operate and for the first time I can really appreciate how traditional chapters would realistically operate.  I always thought that if the 4 battle companies did most of the front line fighting, and were regularly reinforced from the 1st and 6th - 10th companies, why they wouldnt just organize the Chapters into more permanent battalions.  

 

I also like how you worked out the life expectancy and average ages of Space Marines.  Again I am in agreement with your well though out assessments.  I hope to pick your brain on this subject a bit.  So 4 armies, with roughly 6 casualties a year a piece; this amounts to 24.  Per Lord Kallozar's question, over a 100 year period the average Chapter would lose 2400 marines?  That is significant, but we know that the chances of survivability increases the older a marine gets, so most of these casualties will be represented in the younger marines. 

 

This is great, because it makes me wonder about the average Chapter's make up post the Indomitus Crusade.  We know that pre-crusade, most chapters took a beating due to the great rift anyway.  And with your article, it points me in the direction that a Chapter transitioned to Primaris marines, by the current setting in Dark Imperium, would not most of that chapter be made up of Primaris marines?  If a marine who became a battle brother on the onset of the Crusade survived to the present time, he would be at the upper end of Chapter progression, maybe in he veteran company, maybe still in the Battle Companies.  The older astartes, if they survived the Crusade and have not been replaced yet, would be even closer to "retirement" age.  

 

This, in my head anyway, lends credence to what I believe ADB mentioned regarding his upcoming Emperors Spears novel; in how its been a hundred years and the Primaris are just seen as space marines.  (im paraphrasing and extrapolating my own impressions from that lol).  At this point, Primaris marines would be the norm.  Most of the Chapter would be made up of them, and all the new marines entering the Battle Companies at this point would be Primaris.  It all ties together to me.  Very cool.  I think the transition would be organic and smooth at this point, due to the constant attrition faced by the chapter over a 100 year period.

 

This is all just my own opinion and head canon.  I love the setting and I love just thinking about the ramifications of Guillimans return, the Primaris and the Indomitus Crusade and what that could spell for the future of our favorite Chapters.