Let's talk about cities!
How many citizens could an average hive tower (spire?) hold? If a city has one, is it automatically a hive city, or does it need the layers underground as well?
I'm curious because I figured only hive cities had hive towers, until I read Sabbat Martyr. It'd make sense to build them in a city with limited space but overflowing population, I guess.
Hive Cities aren't initially built where there is a large population, they're built and then the population is shipped in to fill them.
Hive Cities are just many layered, sprawling metropolis' that don't have to have a large underground section- a large Hive City could hold about 1 Billion people so I'd imagine a sizeable Hive Tower could hold at least a couple of million.
Originally Posted by Androxine Vortex
I also understand that you need to be at a young age in order to become a SM. What is the max age limit do you think?
Well your body still needs to be developing so I imagine the latest the Astartes could reasonably leave it would be about the age of 16-17, there are precedents for adults becoming Space Marines but the success rate is like 0.1%.