What is "richeut"

Richeut is the earliest known fabliau, dating from 1159.

Although Richeut shares many of the same characteristics as other fabliaux, it has several unique features: 1. It mentions the outcome of a sexual encounter. 2. It breaks the taboo of incest. 3. It is unusually long, containing 1019 lines. 4. It does not use octosyllables, but a tailrhyme strophe. 5. It has character development. 6. The characters of Richeut and Herselot, the maid, exist outside of this text.