Prospero was once the Duke of Milan, but became so "rapt in secret studies" (I.ii.77) that he began to neglect his responsibilities as duke. He was becoming so alienated that he turned many of the responsibilities over to his brother, Antonio.
Eventually, Antonio became so powerful that he wanted to become Duke of Milan officially, instead of just acting as such. Antonio then began plotting with the King of Naples, making deals to "...give him annual tribute, do him homage,/Subject his coronet to his crown..." (I.ii.13-14) if he would help Antonio become Duke.
The King of Naples then had men from his army kidnap Prospero and Miranda during the middle of the night. The men put the two in a bare ship and set them out to sea with nothing; however, Gonzalo (Prospero's councellor) did give Prospero items to travel with, including many of the books from Prospero's library. Once Prospero and Miranda landed on the island, Prospero was able to give his daughter a decent education.
what did antonio do to prosperoand miranda?