The president of the Rehearsal Club came into royalty because of his marriage to which person?
Prince Christian of Schleswig-Holstein Prince Christian of Schleswig-Holstein (Frederick Christian Charles Augustus; 22 January 1831 – 28 October 1917) was a minor Danish-born German prince who became a member of the British Royal Family through his marriage to Princess Helena of the United Kingdom (25 May 1846 – 9 June 1923), the fifth child and third daughter of Queen Victoria and Prince Albert of Saxe-Coburg-Gotha.
Marie Thérèse of France Marie-Thérèse Charlotte of France (19 December 1778 – 19 October 1851), "Madame Royale", was the eldest child of Louis XVI and Marie Antoinette, and the only one to reach adulthood (her siblings all dying before the age of 11). She was married to Louis Antoine, Duke of Angoulême, who was the eldest son of the future Charles X, her father's younger brother; thus the bride and groom were also first cousins.