The Admirable Crichton (Unabridged‪)‬

From the author of Peter Pan:
Lord Loam, a British peer, considers class divisions to be artificial. He promotes his views during tea-parties where servants mingle with his aristocratic guests, to the embarrassment of all. Crichton, his butler, particularly disapproves of this.
Loam, his family, a maid, and Crichton are shipwrecked on a deserted tropical island. The resourceful Crichton is the only one of the party with any practical knowledge. Eventually, social roles are reversed, and Crichton becomes the governor.