Previously unseen photos, exclusively obtained by The Post, of King Charles III getting ready for a milestone moment in the 1960s have been released ahead of his coronation.

In 1969, royal photographer Norman Parkinson photographed then-Prince Charles preparing for his investiture, which took place on July 1 of that year at Caernarfon Castle in Wales.

It was the crowning moment he was formally presented with the title of Prince of Wales.

The photo shoot was done at Windsor Castle when His Royal Highness was just 20 years old, and Grace Coddington, then junior fashion editor at British Vogue, accompanied Parkinson to the shoot.

Parkinson asked Coddington to bring makeup with him in case Charles arrived “flushed from the polo field.”

Coddington was embarrassed as she attempted to powder the prince with makeup using skills she learned in her modeling career and at the Cherry Marshall modeling school.

Charles reportedly attempted to calm her nerves, saying, “I bet you do this all the time,” though Coddington admitted it was her first time.

Parkinson managed to snap a photo of Coddington putting makeup on Charles during the shoot at Windsor Castle.

“If you stole that picture, I bet you would make yourself a fortune,” Charles allegedly quipped in response.

In the photos, the heir can be seen wearing ceremonial robes, a gold coronet and a ring, holding a sword and golden rod — also known as the Honors of the Principality of Wales, the regalia associated with the Princes of Wales.

The Coronet of Charles, designed by architect and goldsmith Louis Osman, was presented to the late Queen Elizabeth II by the Goldsmith’s Company for the Investiture of Prince Charles after the original crown went missing.

The 1969 crown was designed specifically for Charles, and the Prince of Wales insignia is surrounded by 13 diamonds arranged as the constellation of Scorpio, Charles’ astrological sign, according to the Royal Collection Trust.

It’s unknown if Prince William, the newly titled Prince of Wales, will alter the coronet since he is a Gemini, not a Scorpio.

It’s likely that royal fans can expect to see Prince William wearing the Coronet of Charles at the king’s upcoming coronation — marking the first time the crown will be worn and seen by the public in over 50 years.

King Charles’ coronation will take place on May 6, and Katy Perry, Andrea Bocelli and Lionel Richie are set to perform at the musical celebration the following day.

After much speculation, Buckingham Palace announced earlier this month that Prince Harry will attend his father’s coronation ceremony — without Meghan Markle.

“Buckingham Palace is pleased to confirm that the Duke of Sussex will attend the coronation service at Westminster Abbey on May 6,” a spokesperson confirmed. “The Duchess of Sussex will remain in California with Prince Archie and Princess Lilibet.”

Though Markle won’t be in attendance for the coronation, it appears King Charles is subtly putting out a peace offering by prominently featuring a photograph of the Duke and Duchess in his official coronation souvenir program.

It’s been reported that Prince William and Prince Harry will be keeping their distance at the crowning event, as the brothers have not been seen together since Queen Elizabeth’s funeral in September. The coronation will mark the first time Harry has seen his family since the release of his bombshell memoir “Spare.”