Ruritanian romance The Mad King is a work by American author Edgar Rice Burroughs. The parents of Barney Custer are an American farmer and Victoria Rubinroth, a princess of the Luthan race who escaped. On the eve of the First World War, Barney travels to Lutha to witness for himself the place where his mother was born. Barney is naturally mistaken for the king, which causes a great deal of confusion for both him and everyone else. To prevent Prince Peter from assuming the throne, Barney finally permits himself to be crowned king while pretending to be Leopold. To protect Lutha from the approaching Austrians in the second half of the book, Barney is compelled to assume the king's character. He forms a diplomatic partnership with Serbia and personally overpowers the Austrians. One of Prince Peter's goons mistakes the actual king Leopold, who has been his enemy throughout, for Barney and kills him. After finally being married to Princess Emma, Barney decides to continue ruling the Luthas.
