Duke. of Suffolk (Charles Brandon Duke of Suffolk). Henry's closest friend, he married Mary, the King's sister. The King banished him from court for a period after this, as Brandon did not seek his permission to marry Mary. However, he was eventually reinstated at court and was married to Mary, producing 4 children, until her death from Tuberculosis.
Mary Tudor, Henry VIII's younger sister, is not to be confused with Mary Tudor, Henry's daughter, who is known as Bloody Mary. Henry's sister was first married to Louis XII of France, much against her will. She was 19 at the time; Louis was 52. He only lived for 3 months after the wedding -- Mary then secretly married Charles Brandon, the Earl of Suffolk -- a close friend of Henry VIII's.