The saddest part of the Children's Crusade, to my mind, was that many of them were betrayed, not vanquished. As they marched to Jerusalem, they found people who offered them passage by ship or caravan - and upon reaching the middle East, sold them as slaves. And these weren't their muslim enemies, either. The others who reached the Holy Land were either slaughtered wholesale or again captured and sold.

I don't know of any ballads, but there ought to be one.

-J