 Charlotte 's death left the King without any legitimate grandchildren ; his youngest surviving child was over forty . The newspapers urged the King 's unmarried sons towards matrimony . One such leading article reached the King 's fourth son , Prince Edward , Duke of Kent and Strathearn , at his home in Brussels , where he was living with his mistress , Julie de St Laurent . Edward quickly dismissed his mistress and proposed to Leopold 's sister Victoria , Dowager Princess of Leiningen . Their daughter , Princess Alexandrina Victoria of Kent , would eventually ( in 1837 ) become Queen of the United Kingdom . Leopold , by then King of the Belgians , served as long @-@ distance advisor to his niece , and was able to secure her marriage to his nephew , Prince Albert of Saxe @-@ Coburg and Gotha . 
