Royal Heirs Around the World

Crown Prince Frederik of Denmark, center, with his wife Crown Princess Mary of Denmark and their children Princess Isabella, left, and Prince Christian arrive at Mogeltonder Church, May 20, 2012 in Tonder, Denmark. Frederik is not only next in line to the Danish throne, but as a descendent of Queen Victoria, he is in line for the British throne as well. Christian is second for the Danish throne. (Christian Augustin/Getty Images)