The magician Prospero, rightful Duke of Milan, and his daughter, Miranda, have been stranded for twelve years on an island after Prospero's jealous brother Antonio (helped by Alonso, the King of Naples) deposed him and set him adrift with the then-3-year-old Miranda. Gonzalo, the King's counsellor, had secretly supplied their boat with plenty of food, water, clothes and the most-prized books from Prospero's library. Possessing magic powers due to his great learning, Prospero is reluctantly served by a spirit, Ariel, whom Prospero had rescued from a tree in which he had been trapped by the witch Sycorax. Prospero maintains Ariel's loyalty by repeatedly promising to release the "airy spirit" from servitude. Sycorax had been banished to the island, and had died before Prospero's arrival. Her son, Caliban, a deformed monster and the only non-spiritual inhabitant before the arrival of Prospero, was initially adopted and raised by him. He taught Prospero how to survive on the island, while Prospero and Miranda taught Caliban religion and their own language. Following Caliban's attempted rape of Miranda, he had been compelled by Prospero to serve as the magician's slave. In slavery, Caliban has come to view Prospero as a usurper and has grown to resent him and his daughter. Prospero and Miranda in turn view Caliban with contempt and disgust.