A royal biographer revealed Princess Diana “wanted the world” to know her love with King Charles III was genuine, RadarOnline.com can reveal. Author Ingrid Seward said the late princess hoped unveiling love letters from Charles would prove their feelings for one another were authentic, despite rumors and infidelity. Diana and Charles were married in 1981, but split in 1992. The royal divorce was finalized four years later in August 1996, just one year before her sudden death in a car crash in 1997. While the late princess was dating Dodi Fayed at the time of her passing, Seward claimed she wan…