The green children of Woolpit reportedly appeared in the village of Woolpit in Suffolk, England, in the 12th century, during the reign of King Stephen. The only nearly contemporary accounts are given in the chronicle of Ralph of Coggeshall and William of Newburgh's Historia Rerum Anglicarum,1 book I, xxvii, De viridibus pueris. Between that time and their rediscovery in the mid-19th century, the green children seem to surface only in Bishop Francis Godwin's fantastical The Man in the Moone, where William of Newburgh's account is reported.2
The children, brother and sister, were of generally normal appearance except for the green colour of their skin. They spoke in a strange language, and initially the only food they would eat was green beans.3 The boy soon died, but the girl learned to eat other food and eventually lost her green colour. She adjusted to her new life and was baptised, although considered "rather loose and wanton in her conduct".4 When she learned to speak English the girl explained that she and her brother had come from St Martin's Land, an underground world whose inhabitants were green. She became a domestic servant in the household of a local knight from whom Ralph of Coggeshall, himself a local man, learned the story directly.5
One modern theory has it that the mysterious St Martin's Land was the nearby village of Fornham St Martin, about 8 miles (13 km), away, further than many 12th-century villagers would have travelled. The children's accent or dialect may have been sufficiently different as to be unrecognisable, but as there is a common market at Bury St Edmunds, and any reasonable route from Fornham St Martin to Woolpit is likely to have passed through Bury St Edmunds, this explanation seems unlikely.
Another explanation, put forward by Paul Harris in 1998, is that they were possibly Flemish children whose parents had been killed in a period of civil strife. Eastern England had experienced Flemish immigration during the 12th century, but after Henry II became king, the immigrants were persecuted. In 1173 many were killed near Bury St Edmunds not far from the Fornham villages. He also suggests the children may have been from the village of Fornham St Martin where a settlement of Flemish fullers who would have access to a wide variety of dyes existed at the time in question. The children may have fled from their village and ultimately wandered to Woolpit. Disoriented, bewildered and dressed in unfamiliar Flemish costumes, they would certainly have presented a very strange spectacle to the Woolpit villagers. This explanation has its complications, as well. Henry II was expelling Flemish mercenaries, not the merchants and weavers who had lived in England for generations, and few wives followed war, along with their children (although not unheard of). Also, Richard de Calne likely fought against the mercenaries, either as a landowner expelling small groups of raiders or as part of his duty to the crown. It is fairly reasonable to assume that even if he did not know Flemish, he would have figured the possibility of the children being Flemish.
The children's colour could be explained by green sickness, the name once given to anaemia caused by dietary deficiency. Given the possible Flemish origin of the children, a green dye to help camouflage them during a time when Flemings were particularly unpopular seems just as likely.
A similar story, set in 19th-century Catalunya in a village called Banjos, is fictional. Banjos does not exist.