Who or what was said to have arrived in the Suffolk village of Woolpit in the 12th century?

I have read about this before with much more detail although she said it was subterranean it wasn't mentioned as being called St Martin and when you think of it if she learnt English why would it have an English name if not her native tongue. The story is really fascinating though.

So who were the green children of Woolpit? The most likely explanation for the green children of Woolpit is that they were the descendants of Flemish immigrants who had been persecuted and possibly killed by King Stephen or – perhaps – King Henry II. Guys, you should probably go check it in Wikipedia