John F Kennedy and Jacqueline Bouvier

They may not strictly be royalty but they're arguably as close as you'll get to it in American terms. And when JFK married a certain Jacqueline Lee Bouvier in September 1953, it was a suitably grand affair. The ceremony was performed in front of 800 notable guests by an archbishop, after a blessing from Pope Pius XII was read. The reception afterwards was held on a 300-acre seafront estate for more than 1,200 guests. The cake stood four feet tall and the bride wore an elaborate dress of ivory tissue silk and bouffant skirt with more than 50 yards of flounces.