Princess Diana felt 'lonely' just two days after her marriage

Princess Diana's handwritten letter has been revealed.

The letter Diana wrote just two days after her wedding with now-King Charles in 1981, is part of Princess Diana's Style & A Royal Collection, an upcoming auction presented by Julien's Auctions.

As reported by People Magazine, in a note dated July 31, 1981, Diana wrote to Buckingham Palace footman Mark Simpson.

Martin Nolan, co-founder and executive director of Julien's Auctions, called the letter as one of his "favourite pieces."

He said, "It's like a couple of days after she got married. She'd been living in Buckingham Palace as she was transitioning from being a normal person to being a royal and the future queen."

"So she had to learn from the Queen Mother and the Queen about curtsying and all that. But she had fun with Mark Simpson, the footman. And he was about the same age, a little bit older than her. And she talks here, it speaks of how she was lonely when she was in the palace," Martin added.

As per Martin, the letter revealed that the late Princess' early days as royal were not "fun."

In the letter Diana, late and ex wife of King Charles, "Dear Mark, I just wanted to thank you for all your kindness + patience you've showed towards me since I moved into B.P. My stay was made so much easier by your company as it was so terribly lonely + we had so many laughs for that I can't thank you enough.”

"Do hope you were able to enjoy Wednesday + that you liked my dress? I'm off to Britainia tomorrow, what with all those men around. I will have to keep a watchful eye on Evelyn! The bad news is that I haven't eaten any cereal — sob. How am I going to cope without my bowls of cereal....[smiley face]. A large thank you for being you — Much love, Diana," it further read.

It is worth mentioning that the auction will be held on June 26 at The Peninsula Beverly Hills. Princess Diana passed away at the age of 36 on August 31, 1997.