A recently unearthed letter written by then-Prince Charles roughly four months after the August 1997 death of Princess Diana speaks of “unbearable emptiness,” shedding new light on that grief-stricken time.

Penned by hand, the letter was addressed to his friend Peter Houghton and recently fetched $2,000 at auction. The seller was anonymous.

The letter was dated Dec. 8, 1997, and written on Highgrove House letterhead. The envelope’s address included the directive to hand-deliver the missive, according to People.

Charles was writing to share sympathy at the loss of someone named Liz, also gone too soon. Expressing empathy in the letter, he anguished at the loss of one so young — Diana was just 36 when she died in a car accident in a Paris tunnel while fleeing paparazzi — then took on the spiritual implications, quoting a Bible verse and putting his own stamp on the concept of death.

“Personally, I believe that there is another dimension beyond this physical one and that we will be amazed to discover it for ourselves when we are eventually — or at a moment — called upon to make that certain journey for ourselves,” Charles wrote.

Such a message carries even more poignancy today, as 75-year-old King Charles undergoes cancer treatment. Both he and the current Princess of Wales, Kate Middleton, are waging epic health battles. She too has cancer, as she divulged in March after a long absence following abdominal surgery that started out benign.

The sentiments in the letter have been documented in other forums, as Town & Country reported last year.

Journalist Tina Brown, author of “The Diana Chronicles” and a longtime royal watcher, described Charles as “absolutely distraught.” Biographer Christopher Andersen said  the future king was “ashen and trembling” upon learning she’d been killed.

“He let out a cry of pain that was so spontaneous and came from the heart,” Andersen recounted in “King: The Life of Charles II,” according to Town & Country. “Palace staff rushed over to Charles’ room and found him collapsed in an armchair, weeping uncontrollably.”

With News Wire Services