Complex sentence: She was married to Rafael de Medina y Vilallonga in Seville on December 1,1938 and succeeded to the dukedom in 1956 upon her father's death, before it she was know as the XVI Duchess of Alcalá de los Gazules, title given by her father.
Split into simpler sentences: She was married to Rafael de Medina y Vilallonga in Seville on December 1,1938 and succeeded to the dukedom in 1956 upon her father's death. Prior to her father's death, she was known as the XVI Duchess of Alcalá de los Gazules, a title given by her father.