Herodias was the wife of Herod Antipas, the mother of Salome, and a member of the Herodian Dynasty. She is one of the villains in the New Testament, being one of the masterminds (along with her husband) of the plot to murder John the Baptist.
Role in the New Testament
Herodias was originally married to her uncle Herod Philip, the son of Herod the Great. He was the father of her daughter. The two later divorced - Herodias then entered a relationship with her husband's brother and married him. John the Baptist viewed this as immoral (combined with the fact that she married two of her uncles), and criticized Herodias for her actions.
Herodias saw that her husband was enamoured with her daughter, so she gave her to be his mistress. Then Herodias convinced the two to sleep together so she could have John the Baptist killed and his head brought to her.
Salome agreed to this, and upon seducing her stepfather, she asked for the head of John the Baptist, for this was Herodias' wish. John was arrested and beheaded. Salome was given his head, and she brought the head to her mother.