Juan Carlos I ( born 5 January 1938 , Rome , Italy ) is the King of Spain at the moment . His name came from his father ( Juan de BorbÃ n ) , his grandfather ( Alfonso XIII ) and his mother 's father 's name ( Prince Charles of Bourbon-Two Sicilies ) . Juan Carlos I ( baptized as Juan Carlos Alfonso VÃ ctor MarÃ a de BorbÃ n y BorbÃ n-Dos Sicilias ; born 5 January 1938 ) is the reigning King of Spain .