EXCLUSIVE: Princess Diana's Brutal Reaction at Prince William's Christening Revealed on What Would Have Been Her 65th Birthday

Princess Diana's private anguish over Prince William's christening has resurfaced in stark detail, and RadarOnline.com can reveal how she described the day as one that "couldn't have been worse" – a striking reflection shared as her legacy is revisited on what would have been her 65th birthday.

The christening of William, now 44, took place on August 4, 1982, at Buckingham Palace, just six weeks after his birth to Diana, Princess of Wales, then 21, and the then-Prince Charles, then 33, who had married the previous year.

Held in the palace's Music Room on the 82nd birthday of the Queen Mother, the ceremony followed royal tradition, with William dressed in an antique gown commissioned by Queen Victoria and baptized by Archbishop of Canterbury Robert Runcie.

Yet behind the formal images, Diana later revealed she was struggling with postpartum depression and felt sidelined during the planning and execution of the event.

Accounts drawn from Diana's conversations with biographer Andrew Morton describe a profound sense of isolation during what should have been a celebratory milestone.

One source who knew the princess at the time claimed: "She felt decisions were imposed on her at a time when she was physically and emotionally vulnerable."

Another palace insider added: "There was a sense that the occasion became more about royal presentation than her wellbeing as a new mother. The distress she described shows how unsupported she felt within the institution at that point."

Diana's own words, recorded in Morton's Diana: Her True Story book, offer a direct and unfiltered account of the experience.

"Nobody asked me when it was suitable for William," she said about William's christening. "Eleven a.m. couldn't have been worse. Endless pictures of the Queen, Queen Mother, Charles, and William. I was excluded totally that day. I felt desperate because I had literally just given birth."

Diana added: "I wasn't very well, and I just blubbed my eyes out. William started crying, too. Well, he just sensed that I wasn't exactly hunky dory."

The resurfaced reflections have also drawn renewed attention to the early strains in Diana and Charles's marriage, which biographers say were already evident at the time of William's birth.

By the time Prince Harry, now 41, was born in 1984, Diana is said to have hoped a second child might stabilize the marriage. But tensions keep bubbling over, with Diana later recounting Charles's disappointment at not having a daughter.

In Morton's account, Diana said Charles's reaction to Harry's birth was: "Oh God, it's a boy. And he's even got red hair."

She also described a confrontation involving her mother, Frances Shand Kydd, who rebuked Charles after he expressed disappointment.

"Mummy snapped his head off, saying, 'You should realize how lucky you are to have a child that's normal,'" Diana said, adding, "the shutters (came) down" in their relationship afterward.

Diana and Charles ultimately separated in 1992 and divorced in 1996, with Diana later reflecting on how her struggles were perceived within royal circles. "Charles told a lot of people the reason why the marriage was so wobbly was because I was being sick the whole time," she said. "They never questioned what it was doing to me."

Diana was killed aged 36 on August 31, 1997, after a high-speed car crash in the Pont de l'Alma tunnel in Paris. While fleeing aggressive paparazzi, the car, driven by Henri Paul, struck a pillar.

Paul and Diana's companion, Dodi Fayed, was killed instantly.

Diana survived the initial impact but sustained fatal injuries, and despite emergency medical efforts, she was pronounced dead at Pitié-Salpêtrière Hospital a few hours later.