Wikipedia
Subhadrangi
Subhadrangi (also known as Dharma or Janapadakalyani) was, according to Buddhist sources, a wife of the Mauryan emperor, Bindusara and the mother of his successor, Ashoka. The Ashokavadana states that Subhadrangi was the daughter of a Brahmin from the city of Champa. The legends state that palace politics kept her away from Bindusara and when she finally gained access to him and bore him a son, she is said to have exclaimed, "I am now without sorrow", which led to the child being named Ashoka. The name of her second son, Vitashoka (meaning sorrow terminated) has a similar provenance.
The Divyavadana calls her Dharma while the Vamsatthapakasini, a 10th-century commentary on the Mahavamsa, names her as Janapadakalyani.