The special period of fabliau composition appears to have been the 12th and 13th centuries.
The dramatic germ contained in the fabliau and quickened by the mystery produces the profane drama.
But there is nothing in previous literature which exactly corresponds to the fabliau.
Warnatsch (who has also made this last remark) has noted other agreements between lai and fabliau, p. 61.
This suggests the likelihood of a source which combined traits of both lai and fabliau: Warnatsch, pp 62-64.
The French fabliau 'Brunain' takes up the comic rather than the moral aspect of the story.
From the end of one comes many a tearful tragedy; from that of the other nought can be made but a fabliau.
It is a mistake to suppose, as is frequently done, that every legend of the middle ages is a fabliau.
The stories were translated into French, and thus gave rise to the fabliau, which allowed full expression to the esprit Gaulois.
He probably found it in some French fabliau, and treated the story, as usual, so as to make it all his own.