HBO Plots Princess Diana Doc: HBO will premiere “The Princess,” a movie they promise will give viewers “a visceral submersion into Princess Diana’s life in the constant and often intrusive glare of the media spotlight” next month. Director Ed Perkins used only television news footage and other public records to retell the story of the people’s princess and the relationship between Diana and Prince Charles. The film will premiere on Saturday, August 13th at 8 p.m. Eastern Time to coincide with the 25th anniversary of Diana’s death.