In the short story The King of Clubs, Maurania is a kingdom. In the story Paul, prince of Maurania asks Hercule Poirot to help avert a scandal concerning Valerie Saintclair, a woman he hoped to marry. Little information is given about Maurania but it is apparently more than a principality. Paul mentions "The Emperor" and that he had a brother Alexander had also defied "The Emperor" about the choice of woman to marry. Members of the Maurania royal house apparently had what Hastings called "the famous Mauranburg mouth". Given the mention of an emperor, Prince Paul is not likely to be the ruler.
In ITV's 1989 adaptation of the story in Series 1 of ITV's Agatha Christie's Poirot, Prince Paul mentions that Poirot had done a great service for the royal family of Maurania.