Humanitarian. Fashion icon. Mother. Mentor.
These are the words we so often associate with the enigma that was Princess Diana.
However, there's still so much we never knew about the mother-of-two's short yet spectacular life. From the very close-to-home woman Prince Charles dated before marrying Diana, to the secret sibling she forever treasured and her unexpected supermodel connections.
On what would have been Princess Diana's 60th birthday, take a look back at the most fascinating and untold stories from her life.
Long before your Meghan Markles and Kate Middletons, the royals were encouraged to marry blue-blooded aristocrats.
Enter the Spencers – one of England's most revered family dynasties with long-standing ties to the royals.
And as it turns out, Princess Diana's oldest sister, Lady Sarah McCorquodale, dated Prince Charles for nine months in 1977. Nothing like an older sibling to pave the way for the next generation!
While their relationship ended up being pretty innocent, it's still a rather unnerving thought.
Their short-lived romance came crashing down after Sarah gave an embarrassing interview about the Prince.
"Our relationship is totally platonic. I think of him as the big brother I never had. I wouldn't marry a man I didn't love, whether it was a dustman or the King of England," she boldly proclaimed to two journalists.
"If he asked me I would turn him down," she quipped.
As legend has it, bachelor Charles flipped his royal lid when he read her comments and fumed: "You have just done something incredibly stupid."
According to Princess Diana's biographer, Andrew Morton, the then teenager didn't look twice at her sister's beau and her first thoughts about Charles were that he was a "sad man." A prophetic sign of things to come, perhaps?
Looking back on Sarah and Charles' romance, Di reflected: "My sister was all over him like a bad rash and I thought, 'God, he must really hate that.' I kept out of the way. I remember being a fat, podgy, no makeup, un-smart lady but I made a lot of noise and he liked that."
We all know the story of Lady Di's disco fever with John Travolta at the White House in 1985 but the Princess' love of dance stems right back to her childhood.
In fact, Diana longed to be a ballerina but ended up being too tall.
During the early days of marriage to Charles, she was so keen to show off her twinkle toes that she secretly rehearsed a routine with dancer Wayne Sleep for months. Then one night in 1985, Diana and her husband headed to the Royal Opera House to catch a show.
WATCH: Wayne remembers dancing with Diana. Post continues after the video...
At the gala, Diana excused herself from the Royal Box presumably to go to the loo.
Unbeknownst to the Prince of Wales, his wife had changed into a show-stopping silver gown and took to the stage to perform a once-in-a-lifetime jig to Uptown Girl by Billy Joel.
Seriously, why didn't iPhones exist back then?
While there's no footage of the performance, punters claim they were blown away when they spotted the princess on stage.
"We did eight curtain calls… 2000 people with one gasp of breath together, Id' never heard that before," Wayne has since reflected of the moment Diana surprised the audience - her husband included.
"They were in shock and then they realised it was her. I said now you have to bow to the royal box and she said 'I'm not bowing to him, he's my husband! I said, well I have to!"
Sadly, as Andrew Morton writes in his book Diana Her True Story, Prince Charles publicly praised the stunt but behind closed doors, he reportedly chastised his partner for being too much of a show off.
We all know Princess Diana had two older sisters Jane and Sarah, and a younger brother, Charles, the 9th Earl of Spencer, who not only awkwardly shares the same name as her ex-husband but also delivered the most spine-tingling speech at her funeral in 1997 – which was considered to be the almighty rude finger from the Spencers to the Royal Family.
But before Diana was welcomed on July 1, 1961, an older brother was born before her on January 12, 1960.
Tragically John Spencer, who was named after his father, died just ten hours after his arrival due to severe deformities.
John was buried on the grounds of Sandringham church with a young Charles and Diana often visiting the grave of their baby brother and wondering what could have been.
The death of her older brother always hung over Diana, with the Princess once lamenting: "I was the girl who was supposed to be a boy."
Like most teenagers in the '90s Prince William had a crush on supermodel of the moment, Cindy Crawford.
The only difference was, his mum was able to pull some strings and invite Cindy around for a cuppa at Buckingham Palace.
"It was a little awkward," Cindy later told Contact Music in 2006.
"He was a boy, so I didn't want to look too trampy. But I didn't want to look dowdy either. I somehow had to look supermodel for a kid."
Oh, to be a fly on the wall!
Diana was the ultimate royal rule-breaker, even when it came to her wedding.
She may only have been 20 years old when tying the knot with Charles, who was 13 years her senior, but the doe-eyed bride made one genius edit to the stale marriage vows she was expected to recite.
Breaking with royal protocol, the blushing bride removed the order to "obey" her husband and instead promised to ''love him, comfort him, honour and keep him, in sickness and in health.'' Amen to that, Lady Di!
The move was considered rather scandalous (remember, it was 1981) with headlines at the time shouting: "Lady Diana won't vow to obey Charles!"
In 2011, her daughter-in-law Kate Middleton followed her lead and included the same line in her vows to Prince William.
WATCH: A nervous Diana exchanges wedding vows with Charles. Post continues after the video...
When Princess Diana's father the Earl of Spencer secretly wed his second wife, Raine the Countess of Dartmouth, in 1976 behind his children's back they were devastated.
In secret recordings with her voice coach, the royal admits to lashing out at her dad.
"Sarah [Diana's sister] rang me up, she said, 'Have you seen the newspaper?' So I said, 'What?'. 'Daddy's married Raine'. I said, "My God, how do you know that?' 'It's in the Express' [newspaper]."
WATCH: Diana candidly admits to slapping her dad. Post continues after the video...
With fire in her belly, Diana confronted her dad.
"I said, 'Well, we don't like her.' And he said, 'I know that, but you'll grow to love her, as I have," she blasted.
"And I said: 'Well, we won't.' I kept on saying we, not I... I was the little crusader here... and I got really angry and I, if I remember rightly, I slapped him across the face, and I said, 'That's from all of us, for hurting us' and walked out and slammed the door.
"He followed me and he got me by my wrist and turned me round and said, 'Don't you ever talk to me like that again.' And I said, 'Well, don't you ever do that to us again' and walked off."