Valmont was the leacherous bastard half-Elf son of a (presumably) Korstraadi Count who used the power of the Colana Dialiah to seduce three female nobles of the Korstraadi court, including both a Countess and a Duchess (both married). Eventually he attempted to add a fourth noble to his harem and the resulting political fallout lead to him being lynched by the women's jealous husbands.
After he was caught and hanged, one of the husbands took the amulet (not realizing that it was the artifact of a god) and put it in one of his vaults. Soon after, the man that would become the “King of Rogues“ stole it.
The main legacy of The Valmont Affair, as it became known, was an increased mutual distrust among the nobility of Korstraad, which eventually led to the collapse of the governing alliance and the beginning of the Warlords period of Korstraadi history.