(Repost as it went unanswered last time)
TL;DR: Was there really 2 separate "crusades" in 1212 that were led by and mostly composed of kids? Some say yes, other say no as "kids" actually meant "poor peasants", don't know who to believe. Also dead people apparently can write.
Warning: poor grammar ahead
I like to pretend that I'm somewhat well read on the events of the first, second & third crusades since I studied these in college, but my understanding of what happened afterward is at best muddy and at worst full of /r/badhistory.
Still, I always believed that in the year 1212, two 12 years old shepherds, one leaving from France and the other from Germany, each assembled a group mostly composed of kids by preaching in their respective country.
These groups then spectacularly failed to reach Jerusalem, the one from Germany losing around 65% of its 20 000 members while crossing the Alps and the french one ending when the 30k or so kids composing it were told to go back home by Philip II
According to a french monk, after this there was 7000 or so kids on the initial 30k who decided to go ahead anyway with that whole "going on a crusade thing" and they supposedly end up being made slaves on the boats of two rich french merchants who told them that they'd help them reach Jerusalem, a few of them died when 2 of the "expedition's" 7 boats crashed during a storm and the remaining kids were then sold.
From my understanding that last part widely recognized as having never happened since we only have that one monk's writing
mentioning it.
(Weird thing I just realized, this story is said by some to have been written between 1260 & 1295 by Alberic of Trois-Fontaine, but he died somewhere around 1252 from what I can see.)
But now I'm reading a little more on it and it seems that no one agree on what really happened or even if it happened at all (see the wikipedia article on this, which I may have used to refresh my memory while writing this). Could anyone shed some light on this for me please?
I have heard the same stories that you've heard about the Children's Crusades and believe that it is true. There are, of course, dissenters who are quick to say that these were uneducated peasants. But, there was a Peasant's Crusade (People's Crusade) led by Peter the Hermit that was actually comprised of poor, common adult people. The difference in naming them seems striking, as there is obviously a difference between children and peasants or people.
I also encountered this piece of medieval history in a European folklore class, which discussed how the Pied Piper of Hamelin may have been derived from the enigmatic leader of the German originating crusade and his collection of children as he wove his way through Europe to the Holy Land. Folklore tends to lean on the side of realism in many cases and stripped of their fanciful trappings, often hold a great deal of truth. The story emerged in the late 13th century and the loss of the children is almost certain to be true, as later records of the town note their absence. Combining this with the other 50 or so accounts (Gesta Treverorum, Annals of Marbach, Annales Placentini Guelfi, Annals of St. Médard, etc.) lends weight to the idea that the Children's Crusade did happen, but doesn't necessarily mean that it was entirely comprised of children. I imagine, caught up in the religious fervor of the time period, that many adult people accompanied their children or simply joined in.
We also should remember that "children" were most likely to be pre-pubescent, as adolescents would have been considered adults for the most part. The presence of a great number of children, even in the company of adults, would have been adequate to give the impression that it was primarily children and been very powerful religious propaganda. Sort of a "see how these innocent children go to fight for the Holy Land, what are you doing about it?" kind of thing.
With history, these mysteries are always the kind of thing that need more investigation and a better look. Ideally, remains would be found in the Arab world that genetic testing could link to German or French ancestry to solidify the accounts with scientific proofs. Until then, the paradigm is there to be shattered by anyone who likes solving these sorts of things.
Here's some additional materials you might enjoy:
http://www.jstor.org/stable/1835076
http://www.fordham.edu/halsall/source/1212pueri.asp
http://www.gutenberg-e.org/maclehose/printable/A_Tender_Age_Chapter4.pdf