Rebuilding Civilisation after the Bang

[Scholar]

Hiya,
the setting I'm currently working on, Godefell, is by and large post-apocalyptic, although not post-nuke. anyway, that's not the point, what I was wondering is: how will people react when their power structures vanish.
before the boom, the main cultures were at a development stage similar to late 16th century western europe: feudal elements mixed with clerical authority and some uppity peasants. the only major race the human nations interacted with were the dwarves, who weren't all that different.
the world as it is now, is hostile to humans. the land and the creatures have changed, the days get shorter and the nights longer, it is getting colder and winter is a night that lasts 3 months. oh, and he night is quite literally dark and full of terrors.
now here are the social structures that came to my mind:

magocracy: there were never a lot of mages, but those who still live have to be really powerful, so people will flock to them, serving them in exchange for protection.

tribes: remote communities that were spared most of the destructions will change into sort of tight-knit tribal communities with, to use a not well-liked term, socialist world-view. this is problematic, as most small communities will fall into the 300-500 inhabitants range, not giving them much genetic diversity.

might makes right: groups of people who control pre-bang armouries or castles with intact stocks will have command over everything from swords over crossbows to light field artillery. this, combined with the general loss of technologies like steelcraft will give rise to pseudo-aristocrats or warlords.

[Stargate525]

magocracy: there were never a lot of mages, but those who still live have to be really powerful, so people will flock to them, serving them in exchange for protection.

That's the reason castles usually developed towns around them, so...

tribes: remote communities that were spared most of the destructions will change into sort of tight-knit tribal communities with, to use a not well-liked term, socialist world-view. this is problematic, as most small communities will fall into the 300-500 inhabitants range, not giving them much genetic diversity.

that number is more than enough to stave off the effects of inbreeding, and it's not like they're completely isolated, right? If that's your only issue with this setting, you've got no problems.

might makes right: groups of people who control pre-bang armouries or castles with intact stocks will have command over everything from swords over crossbows to light field artillery. this, combined with the general loss of technologies like steelcraft will give rise to pseudo-aristocrats or warlords.

with this setup, nothing has changed from your pre-bang setup, so that's fine as well. The only issue with this is that it's based on fortifications, and requires land outside of these fortifications to survive.

[Gamer Printshop]

While helping to develope another designer's campaign world at a different D20 campaign building site (not to be named :P) It was post apocalyptic but during the Greco city-states era, one direction things seemed to go was very religious. The masses turning to the gods in a fundamentalist way, a dangerous way, counter to the surviving church was heavy in such a setting - and I see your campaign world going that way too.

There also should be a constant power struggle, as one chieftan/leader trys to usurp his neighbors, trying to reestablish city-states, sovereignties - whatever existed before, but not of the old lines. Its time for the new guard. There would be a rise of many petty states.

Those that have supplies become power centers and perhaps powerful thieves guilds controlling the necessities to survive.

All the old sins of slavery would spread as warlords need crop growers and empire raisers.

There might be a sense of starting over, but into a dark future...

[Midgardsormr]

The obvious places to look for inspiration are Europe from around 450 to 800 A.D, following the fall of Rome, and the Warring States Era in Chinese history, following the decline of the Eastern Zhou Dynasty.

Note that in both of those cases, although the tremendous political vacuum resulted in a great deal of social unrest, there was also much cultural advancement that accompanied it.  Old power structures tend to preserve the status quo, stifling innovation and cultural advance.  In the absence of such authority, people develop new technologies and philosophies rapidly in order to cope with circumstances.

To be more specific, it took the end of Roman hegemony to enable advances in mill and plow technology.  Prior to that, manual labor was done by slaves; there was little incentive to develop new technologies to make things easier.  With the collapse of the economy and government that made slavery efficient, the patricians and educated plebes found themselves forced to participate in agriculture.  Being Romans, they applied that knack for engineering that had previously been used almost exclusively for warfare and commerce and applied it instead to the new challenges they faced.

In China, the most fertile period of philosophical growth was near the end of the Warring States period.  The Hundred Schools began with Confucius at around 500 B.C. and ended with the death of the Qin Emperor in 206 B.C, shortly after which point Confucianism became the official doctrine of the Empire, a circumstance that lasted until 1905 A.D.: about 2,000 years of philosophical stasis due to the presence of a powerful authoritarian structure.

So, to reiterate my point, although life will be hard and vicious, there may be places where technology and culture are flourishing.

[Matt Larkin (author)]

In the case of Rome, the Christian Church wound up taking over many functions that were once overseen by the government. The mages in your setting could do similar things.

[Scholar]

I think I'll have the Mage Lords be a force of progress, even if they are a bit tyrannical, rivaled by nonmagic Warlords who want to keep people as helpless as they are.
For the religious angle, enter the one church that survived the bang. :)
It would be great, if you could also help me with the next step.