Louis-Antoine, the Duc d'Angoulême was the nephew of Louis XVI, being the oldest son of the Comte d'Artois. The Comtesse d'Artois, mother of Louis-Antoine, gave him over to the servants to raise and he had many health problems. He was painfully shy, awkward, unattractive, unsocialized, and impotent - all the qualities usually and unfairly attributed to his uncle Louis XVI. He was betrothed as a child to his first cousin Madame Royale, Marie-Thérèse-Charlotte de France.
After her release from prison and temporary stay in Vienna (where she almost married Archduke Karl), Marie-Thérèse married Louis-Antoine in Mitau in Courland (Latvia) in 1799. Their uncle, Louis XVIII, wrote love letters in Louis-Antoine's name to Marie-Thérèse in order to get her to marry her cousin because he needed her with him in order to further his goal of gaining the Throne of France. Marie-Thérèse discovered too late that Louis-Antoine did not write the love letters. They had a marriage in name only but Marie-Thérèse never sought an annulment.
Louis-Antoine is often known as Louis XIX because he was king for about 10 minutes after his father abdicated; then he himself signed the abdication as well. An eccentric and pathetic character but a frustrating one....His wife, Marie-Thérèse, stayed with him to the end of his life (1844); they had become tender companions and best friends over the years in spite of everything.