Elizabeth at 90: A Family Portrait is narrated by the longest-serving heir apparent in what?
Elizabeth at 90: A Family Portrait:  It was produced by the BBC and directed by John Bridcut, and narrated by Charles, Prince of Wales. Charles, Prince of Wales: Charles, Prince of Wales (Charles Philip Arthur George; born 14 November 1948) is the eldest child and heir apparent of Queen Elizabeth II. Charles, Prince of Wales:  Known alternatively in Cornwall as Duke of Cornwall and in Scotland as Duke of Rothesay, he is the longest-serving heir apparent in British history, having held the position since 1952.
i don't know