How Prospero brings his brother and the King of Naples to the island?

Shakespeare needed a way to bring his brother and the rest of the "cast" to his island. Basically he uses his magic to conjure up a storm . The crew end up cast ashore on his island. Prospero tells his daughter he was once the Duke of Milan, but his brother Antonio usurped his position after Prospero had Antonio manage his state. Prosper means to avenge himself.