How long were Agatha and her father confined in prison?

The deLacey family were not really confined in prison. Rather they went to see Safie's father when he was accused of a crime he did not commit. They wanted to help him escape, but before they could do so, their plot was found out. They were exiled from their country and stripped of all their wealth. Safie did not want to go back to Turkey once her father was out of jail so she escaped and found Felix and Agatha in Germany where they were living out their exile.