"The Emperor's Fan" is a fantasy short story by American writer L. Sprague de Camp. It was first published in Astounding: The John W. Campbell Memorial Anthology, edited by Harry Harrison, in 1973.
Tsotuga the Fourth, emperor of Kuromon, is a competent but dull ruler, notable only for occasional temperamental outbursts. Having poisoned his father to attain the throne, he finds his dreams haunted by his father's spirit, who prophecies a dreadful doom for him. Seeking some impregnable magical defense, Tsotuga is heartened when his crony, Reiro the Beggar, tells him that just such a weapon is said to be in the possession of the sorcerer Ajandra, from the tropical empire of Mulvan.