The president of the Rehearsal Club came into royalty because of his marriage to which person?
Rehearsal Club (London):  It was founded in 1892 by the Rev. John Fenwick Kitto, vicar of St Martin in the Fields, with the support of Prince Christian, who became the club's President. 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.
Princess Helena