This is a fairy tale about a princess whose father goes mad with grief over the loss of his wife and tries to marry his own daughter. To avoid this she runs away from home, in a donkey skin dress, to become a servant in a foreign kingdom. Kind of like The Goose Girl.
http://www.surlalunefairytales.com/donkeyskin/index.html Note the books on the side, they are retellings of the tale.
http://www.donkeyskin.com/book/2358-f2-donkey-skin This is not as descriptive as surlalune, but you get to flip the pages 😛 For the younger readers