Task: Question Generation
Input (English): Context : Princess Lilian of Belgium (née Mary Lilian Baels, 28 November 1916 -- 7 June 2002) best known as Lilian, Princess of Réthy, was the second wife of King Leopold III of the Belgians. 
Subject : Lilian, Princess of Réthy 
Relation : spouse
Output (English): What is Lilian, Princess of Réthy's spouse's name?