From a Latinized version, Rudolphus, of the Germanic name Hrōdwulf (see Rolf). It was introduced to the English-speaking world from Germany in the 19th century. Rudolf was a hereditary name among the Habsburgs, the Holy Roman Emperors and rulers of Austria, from the Emperor Rudolf I (1218–91) to the Archduke Rudolf, Crown Prince of Austria-Hungary, who died in mysterious circumstances at his country house at Meyerling in 1889. Rudolf Rassendyll was the central character of Anthony Hope's adventure stories The Prisoner of Zenda (1894) and Rupert of Hentzau (1898), in which he is an English gentleman who bears a great physical resemblance to the King of Ruritania, to whom he is distantly related. He successfully impersonates the king for reasons of state. In the early 20th century the popularity of this name was further enhanced by the American silent-film actor Rudolph Valentino (1895–1926), born in Italy as Rodolfo di Valentina d'Antonguolla. It has not been used much in recent times, perhaps being inextricably associated with ‘the red-nosed reindeer’ of the Christmas song.