Board Thread:Warhammer 40k General Discussion/@comment-25618639-20150723053637/@comment-6078851-20150727164556

they indeed have incredible longevity but are still susceptible to the infirmities of old age - if they ever manage to reach old age.

the eldar are not effectively immortal though: their average, uninterrupted lifespan is around a thousand years, and many eldar reach old age and die from it - maybe not as many these days as used to die from old age as they now die in combat far more than from age. the term 'effectively immortal' can't be applied to the eldar as they have demonstrated for millenia that they aren't.

to be pedantic 'effectively immortal' also can't be applied to astartes despite how much of the lore describes them as such. until one dies from old age then it can be considered that they may not die from old age, but they die all the time in a multitude of ways - the reason no-one knows if astartes die of old age is because almost all of them die long, long before age becomes a factor, so that isn't immortal, effective or otherwise.

the only immortals in the imperium are perpetuals, and the only ones that are verifiably perpetual are vulkan and grammaticus (i think there's at least one more but these 2 are the only ones i know of).