Why is the Night's Watch so depleted at the start of ASOIAF?

Question

At the start of AGOT, the total number of the Night's Watch is said to be less than a thousand. During Aegon's conquest, the Watch numbered ten thousand men. Out of the nineteen castles on the wall, only three are manned today. Castle black itself is once said to have housed 5000.

This rapid deterioration doesn't make sense to me from a world-building perspective. The NW have continued to maintain themselves pretty well for nigh on 8000 years (if the tales can be believed that is, Sam Tarly finds no written evidence of Lord Commanders earlier than #673, which suggests that 8000 years may be an inflated 'legendary' number).

Whereas in the real world, one of the oldest and most venerable institutions, the Catholic Church, has been around for less than 2000 years and has been administered by ~200 popes. The Night's Watch has had a few rocky years, sure, but for it to maintain itself so well for so long and then deteriorate only in the last 300 years seems strange to me.

The NW has two purposes. The ostensible one of defending against the Others, and the (arguably much more real, at least at the start of AGOT) purpose of serving as a dumping ground for the 'losers' of Westeros. By 'losers', I mean the people on the losing side of various wars and political battles, as well as criminals and n-th sons of noble houses with nothing to inherit.

I am currently reading through Fire and Blood, and was struck by one chapter, where an armed revolt of members of the Faith were defeated by Maegor, and 2000 brothers were forced to take the black. Those sorts of numbers don't exist in the recent histories it seems.

One would expect that after Robert's Rebellion, there would be a surfeit of defeated Targaryen loyalists who were forced to take the black, but apart from a smattering of named characters (including Ser Alliser Thorne), there seem to be hardly any Night's watch recruits from recent wars.

Given the way the Night's watch is continually bolstered by the losers of wars and by criminals and other people who elsewise have nothing going for them, why, at the start of AGOT, is the force so depleted?

Answer 1

Apples and Oranges

You can't really compare the Watch to the Papacy. The Watch isn't a religion, and that too World's largest religion. The Papacy's structure is different, it's role in politics was different, it's methods of generating revenue were different. If you want to compare them to anything, compare them to various Military orders. You'll notice they all eventually declined in numbers, influence and many such as Knight's Templars actually went extinct.

Sources of Income

Night's Watch relies on Brandon's Gift and New Gift for most of its maintenance. Of course that alone doesn't suffice for all their needs so they need to ask the Crown and lords to give as much assistance as they can.

You're correct that when Aegon the Dragon came, Night's Watch had 10,000 men under Lord Commander Hoare's command. But 300 years is a long time. Just because they had that many men back then doesn't mean they did well, for example just a few Decades after King Aegon's death, when his grand-daughter Queen Alysanne visited the wall, the Lord Commander had to apologise to her Grace for extremely poor food and living conditions, the Watch couldn't afford any better.

The Problems

The first problems the Night's watch faced were structural decay and organisational stagnation. Night's Watch stuck to the old routines for no better reason than tradition. For example, they kept maintaining extremely costly forts like Nightfort even though they struggled to pay for it, simply because the Castle was as old as the Watch and there were no better alternatives. Queen Alysanne paid for a new, smaller Castle to replace Nightfort, which was then abandoned. The other Castles were similarly abandoned because the Watch lacked the funds (And later men) to keep them operational. The thousands of members of Sons and Stars that you mention were forced to join the Watch, we have Lord Stark's testimony that the Night's Watch couldn't feed them and yet they were forced upon them. Presumably, to make wiggle room in their budget to account for these new mouths, they must have had to either raise taxes (Which will force smallfolks to leave) or abandon castles to save the operational costs. This example you cited from Maegor's reign is an anomaly in any case. The people he forced to the Watch weren't common people, they were members of the militant orders of the Faith, they were not going to go back to their homes if Maegor was to treat them like common people. The zealots would have picked up their swords again because that's the life they knew where as a common man knows his family life.

The Stagnation and Recruitment

Also the stagnation like insistence on Swordplay during training which is a relic of the days when 2 in 20 brothers were Knights persisted as late as Jon's day. Knightood remained to be seen as an important part of the Watch and Knights were preferred for Commands of different Castles and missions. But as it happens, Knighthood is an Andal institution and Andal faith prevails South of the Neck. With time, the threat of Walkers passed away from realm of history to legends and myths. The fact that Night's Watch became an arctic penal colony for criminals for most part didn't help either. It was no longer seen as a honour to serve in the Watch. It was now a place for the misfits, the criminals, done old men, bastards etc. What honour could be found in that company? We have two examples one from Prince Rhaegar's days when a Night's Watch brother came calling to Harrenhal and asked if any man would honour his house by taking the black. None answered. Then Eddard Stark asked the same question while serving as Robert's hand, none answered. At that point, Eddard was forced to give Yoren his pick of the Dungeons. As TenthJustice shrewdly observes, the largest and richest populations dwell down South. And while the Wildlings beyond the wall may be a small threat to tranquility of the North, they pose no threat to the Southern Kingdoms. And since the Watch remains the first shield of the North, they are still honoured by the Northern Lords and folks. That is not the case in the South.

Now that we have covered why did the Watch had to abandon castles, let's go over how did it come to pass.

The Decline

This is more like did the Chicken come first or the egg? As already mentioned, NW relies on the Gifts (Both of them) to maintain themselves. The smallfolk who work and live those lands pay taxes directly to Night's Watch rather than Winterfell or the Crown. But as Night's Watch dwindled in quality and quantity, Wildling raiders became more frequent visitors and more deadly. The raids virtually forced entire population of the Gifts with exceptions of few small villages to leave en masse for South to safety of some Lord's power, rather than the Watch's power. And so the Watch lost its main revenue source. Which must have resulted in more cuts, more castles abandoned, which in turn meant more raids but now the raiders went as far as Umber lands in realm proper. Now with ability to barely feed the men they had, Night's Watch would naturally have to tone down the recruitment drive. And indeed we see just a handful of wandering brothers who go around the realm to seek more men. And Apparently, the only men they can find are criminals, orphans and starving. So decline in taxes causes decline in quality/quantity, decline in quality causes upsurge in raids, upsurge in raids causes upsurge in emigration, upsurge in emigration causes decline in taxes. We keep going in circles. Nevertheless, it is evident that taxes, quality and raids are tied to each other.

Robert's Rebellion

You're incorrect in assuming that Robert's Rebellion should have provided fresh manpower to Night's Watch. Robert pardoned every Targaryen loyalist. People lost parts of their lands but none lost their heads or titles. The only Targaryen loyalists we see on the Wall were sent there by Tywin Lannister, presumably after the sack of King's Landing (When Robert was still on the Trident, recovering from his wounds), not by Robert. And before Robert's Rebellion, the last major war was the War of the Nine Penny Kings which was fought on Stepstones, a foreign land during King Jaehaerys II's reign. No Prisoners were sent to the Watch from the Stepstones as far as we know. Smallfolk and unlanded knights usually are spared the punishments at end of the wars anyways, it's only the nobles and landed knights who get punished by attainder, exile, handing over captives, forced to take the black etc. Anyways it is safe to assume that there was no recent influx of fresh levies in Night's Watch ranks from the walls except for minuscule infusion of a couple of men like Aliser Thorne and Jarmen Buckwell etc.

Answer 2

So I've come up with an answer that I find sufficiently satisfying.

Institutional decay doesn't just happen

It's a common trope of fantasy that things 'just used to be better', which fits well with our intuition about real life. (An intuition, which as it happens, is often completely wrong). I think GRRM recognises and plays to this. The characters in the Age of Heroes (Bran the Builder, Symeon Star Eyes, Azor Ahai, etc.) are almost certainly nowhere near as epic as portrayed, if they ever existed at all.

In the absence of war and famine, societies typically flourish. If an institution is decaying, there has to be a reason for it. American manufacturing is in a decay because the Chinese can do the same for cheaper. Stamp collectors are a dying breed because no one uses the post for personal correspondence anymore, now that we have the internet.

So I reject the notion that the Night's watch are in a state of decay 'just because'.

To maintain the culture of an institution, a steady (and relatively small) stream of new members is necessary

New recruits to the night's watch do not initially share the values, nor understand the culture of the night's watch. By being in the minority, they can be forced to assimilate to the culture. Any new recruits who were previously members of a specific faction (they owe their allegiance to a specific lord or to the Seven) who might be inclined to bring their own value systems along can be quashed by the majority rest of the night's watch with little relative pushback.

However, when a cohort of new recruits becomes a significant minority or even a majority of members, that's when the institutional decay starts. The 'executive' of the night's watch - the commander, higher officers and all those responsible for management of the watch - no longer have the force of numbers to carry out arbitrary punishment. To punish a popular but harmful new recruit is to court violent reprisals.

There are many examples in the real world of close knit cultures being 'ruined' by too many new members. The first one that comes to mind is the september that never ended, referring to the state of the nascent internet in 1993. Before then, usenet users were primarily academics, and each year (starting in september) a new cohort of users would arrive, and would typically be disruptive for a while before learning the etiquette of usenet. In September 1993, the launch of AOL meant that the influx was much greater than before, and the 'old guard' was powerless to teach the new users the ways of internet etiquette.

A similar effect can be seen within broader culture when the Baby boomers came of age. A lot of the previous culture (both the good and the bad) of the people who lived through WW2 was rejected by the Baby Boomers, and because of their sheer force of numbers, that culture shift persisted.

So how did things change for the worse after the conquest?

To quote Maester Aemon in AGOT (his "Love is the death of Duty" speech):

In the days when the Seven Kingdoms were seven kingdoms, not a generation passed that three or four of them were not at war.

I think this is the key. With constant war comes a constant stream of defeated nobility heading towards the wall.

After Aegon's conquest, the dynamics change in two crucial ways:

• Wars are less frequent and much bigger
• Peace can last for longer than a generation

The end result of this is that the influx of quality recruits to the Night's Watch is very clumpy and unpredictable. Large numbers of new recruits will result in the decay of the culture and values in the ways that I explained above. When Maegor sent 2000 of the faith militant to the wall, that would have had a huge impact on the culture there, even though that 2000 would still have been in the minority at the time.

Turnover on the wall is high

The wall is not a good place for growing old. There's not enough info in the books to make a reliable actuarial estimate on the mean lifetime of someone after taking the Black. It stands to reason though, that not many people would make it past 20 years of service.

During a time of long peace, the lack of quality recruits from defeated households could be disastrous. So the recruiters have to make up the shortfall with criminals, broken men and other such recruits who are unacquainted with discipline and following orders. I don't have any quotes with me to back this up, but I suspect the Night's Watch has always accepted and made use of criminals. However, these criminals can always be beaten into shape by the rest of the Night's watch.

The crucial change comes when the Night's Watch is forced, through a time of peace, to recruit primarily from criminals.

That changes the culture, and earns the Night's Watch an unsavoury reputation. As other have suggested, once the Night's watch is associated with criminals, this results in a positive feedback loop. Men of honour are less likely to see taking the Black as a noble pursuit, and Lords are more likely to see it as a fitting punishment for their criminals and prisoners. I think this goes a long way to answering why the Night's watch is depleted at the start of AGOT, but it doesn't completely answer it.

The Night's Watch is the only thing standing between the realm and what lies beyond, and it has become an army of undisciplined boys and tired old men

Because of the high turnover at the wall, you don't necessarily need to look for longterm declining trends to explain the low population. Recent events are sufficient.

As @Aegon mentioned in his answer:

You're incorrect in assuming that Robert's Rebellion should have provided fresh manpower to Night's Watch. Robert pardoned every Targaryen loyalist. People lost parts of their lands but none lost their heads or titles. The only Targaryen loyalists we see on the Wall were sent there by Tywin Lannister, presumably after the sack of King's Landing

I think that pardoning these Targaryen loyalists deprived the Wall of much needed recruits, and was likely one of the biggest contributors to the lack of men serving there. The preceeding loss of respect for the Black probably influenced Robert's decision, but an arbitrary decision it still was.

Which is why the Night's watch is described as such by Maester Aemon. It's missing the cohort of middle-aged men whose combination of experience and fitness the Wall needed most. The cohort that would have been filled 15 years ago had Robert made a different decision.

Answer 3

Taking the black is a choice, to address Roberts rebellion it is likely that once it succeeded everyone who was able decided to bend the knee and Robert accepted their fealty, only the most die hard loyalists would choose to take the black given the option of swearing fealty to the new king and retaining their lands and titles.

The amount of criminals was most likely never enough to maintain the ranks of the watch.

Only in the north is it seen as honorable for lesser sons to take the black in the south lands lesser sons most likely choose to be knights or anything that does not involve freezing your A** of at the wall.

TL:DR

The watch is simply in decline once it was seen as honorable to take the black in recent times it is seen simply as a place to sweep the trash.