Who is Aurangzeb from Beneath a Marble Sky: A Novel of the Taj Mahal and what is their importance?

Aurangzeb is the antagonist in the novel. He is the second son of Shah Jahan and Arjumand. From the beginning of Jahanara's story, Aurangzeb shows himself to be vengeful, envious, and cruel. Jahanara and Dara talk often about their brother, discussing at first what they must have done wrong to make him so hateful. Later, Jahanara must scheme both with Dara and behind his back to defend her family from Aurangzeb's ambition.