Tragic Facts About Kathleen Cavendish, The Lost Kennedy

Dancy Mason

On the surface, Lady Kathleen Cavendish seemed to have it all—but once anyone finds out her real name, they know much differently. Born Kathleen Kennedy, she was the sister of John F. Kennedy and the daughter of the infamously cursed clan. And make no mistake, she was cursed: Although she had all the inborn elegance of her family name, Kathleen’s end was both scandalous and brutal.


Kathleen Cavendish Facts

1. She Was American Royalty

Born Kathleen Kennedy, Kathleen’s mother and father were the prominent Joseph and Rose Kennedy, and the famous clan went on to produce luminaries like Kathleen’s ill-fated brothers President John F. Kennedy and Senator Bobby Kennedy. Yet as we’ll see, Kathleen was just as much a victim of the horrific “Kennedy Curse” as her siblings, and her nightmare started early.

2. She Was A Troublemaker

The Kennedys were no easy family to grow up in, not for Kathleen anyway. Her mother and father were ambitious, controlling, and expected their children to adhere to strict Irish-Catholic morals, all while doing the family proud. Kathleen, however, was a free-spirited young girl, even earning the name “Kick” for her boundless energy, and she often clashed with her parents. Only…it got much worse than that.

3. Her Family Was Horrific

For all that the Kennedys were about family values, they hid dark secrets. In the end, they weren’t just overbearing; they were downright dangerous. Infamously, when Kathleen’s sister Rosemary proved to be intellectually disabled, her parents hid it from their hoity-toity social circles and then forced the girl into a botched lobotomy that left her nearly unable to speak. Yes, REALLY. Oh, but there’s more.

4. Her Father Was A Mess

If the Kennedys held traditional Catholic values, they weren’t necessarily moral values. There was a real “me man, you woman” vibe in the house growing up, and Kathleen had to watch as her father Joseph cheated constantly on her mother, going so far as to flaunt his mistresses in front of her and the children. And believe me, these were no ordinary “other” women.

5. She Grew Up Around Starlets

Joseph Kennedy had a penchant not just for illicit affairs, but for illicit affairs with Hollywood starlets. Among the names in his little black book were Gloria Swanson, the future star of Sunset Boulevard, and Tinsel town scandal-maker Marlene Dietrich, whose outspoken and risque nature outraged moviegoers. Most scandalously, however, Joseph involved his daughter Kathleen directly in his flings…

6 Her Father Used Her

Not content with parading his mistresses around his wife, Joseph started letting the various children involved play together; at one point, Swanson’s daughter, also named Gloria, came over for a Halloween party at Kathleen’s house. As one biographer put it, “Kick was intrigued to meet the daughter of the world’s most famous movie star … she liked her new friend.” Ew, dad. But Kathleen soon had to face an even more disturbing truth.

7. Her Family Creeped People Out

Eventually, Kathleen’s father seemed to move on from screen sirens….to his daughter’s own friends. The Kennedys had a screening room in their basement, and one day the teenage girl realized that none of her gal pals wanted to go down there. Why? Because if her father caught them alone or unawares, he would “touch them and pinch them.”

Yep, Kathleen got the furthest thing from a stable upbringing, and it forced her to make a heartbreaking choice.

8. She Was A Natural Rebel

In the middle of this turmoil, a defiant Kathleen steadfastly “chose” her mother growing up, acting as the matriarch’s “protector” as her father openly philandered and strayed. It may have been the right decision, but it certainly wasn’t the conventional one in their conservative family—and as we’ll see, her mother didn’t exactly thank her for it. For now, though, Kathleen had more pressing issues to worry about.

9. She Wasn’t Pretty

Horrific family aside, Kathleen had troubles of her own, at least in the glittering, picture-perfect debutante world. Namely: She wasn’t conventionally beautiful. Her own biographer called her “quite plain,” with a strange, high stoop to her shoulders, a thick neck, and frizzy hair. At five foot three inches and slender, her figure apparently wasn’t much to write home about, either. But Kathleen did have one thing to recommend her.

10. She Had A Secret Weapon

If she wasn’t the most dazzling girl on the block, Kathleen was nonetheless a darn good sport. Her energy kept up as she grew coltish, and she became a fun-loving, good-time gal who was able to laugh at herself and delight the people around her in the process. Thanks to all her brothers, particularly future President John F. Kennedy, she also became quite the tomboy. Except this was actually the beginning of a fiery scandal.

11. The Boys Loved Her

While she was in school, Kathleen loved to get rough and tumble with her brother and his friends, so maybe it was inevitable that these strapping young men started to take notice of her, and soon enough they were knocking at her door for dates. Worst of all (at least for her pearl-clutching family) Kathleen liked the boys back, and developed a thing for “red-blooded American jocks.” Alarmed, her mother made a desperate move.

12. Her Mother Locked Her Up

In order to get Kathleen away from the temptation of those beautiful, square-jawed New England boys, Rose Kennedy whisked her daughter away not just to an all-girls school, but an all-girls convent school. In other words, it was pretty much guaranteed to tamp down the socialite’s budding sexuality and lock her away in a tower.

Or so Rose thought…but she quickly found out how wrong she was.

13. She Liked Rich Boys

Inevitably, the Kennedy daughter did start dating, and her choice was telling. Her jock days apparently over, Kathleen took up her family’s expensive tastes and began seriously dating Peter Grace, the heir to a chemical manufacturing business. Still, it must not have been good enough for her demanding parents, because they were about to put her through an enormous change.

14. She Was A Diamond Of The First Water

Just after finishing school, the teenage Kathleen started to make her mark on high society—and it was quite a mark. When she was 18, her father became the US ambassador to Great Britain and took Kathleen along with him to the foreign country. Almost instantly, she became a sensation in London, and her peers even named her the “debutante of 1938” after she attended the prestigious Queen Charlotte’s Ball. Then again, there was a big reason for her success.

15. She Was Brash

Once more, Kathleen’s lust for life and her forward nature helped turn her into the belle of the ball even when she didn’t have the looks. A brash American was already a delicacy in stuffy British aristocratic society, but a brash American like Kathleen was something else entirely. “She did not hang back shyly or demurely,” her biographer writes, and everyone was enchanted.

Kathleen was coming into her own…until a rude awakening hit her over the head.

16. She Had To Flee France

In 1939, just a year after Kathleen had charmed seemingly all of Europe, WWII broke out. It created a bone-chilling situation. Ever the socialite, Kathleen had been staying with a friend at her family home in France, AKA not at all far away from Germany. When the news of war reached her, she and her companion had to rush back to England.

Sadly, it wasn’t to the kind of safety she wanted.

17. She Wanted Her Parents To Abandon Her

When the dust settled, the Kennedys were adamant that they had to return stateside and save Kathleen’s father Joseph from any danger in his position as US ambassador. Kathleen, however, had other ideas, and was heartbroken at the thought of leaving her beloved England behind so soon. She begged her parents to leave her in Europe while they went home, but their response was ice cold.

18. Her Family Forced Her Home

The adventurous Kathleen was willing to face down her fears about the coming conflict, if only to stay a little longer. Besides, there also might have been a man involved—but her parents likely didn’t know about that until much later. In any case, it was all for naught: Her father declined to entertain any of her appeals, and forced her to head back to America in the fall of 1939.

She had no choice but to obey, but her rebellion came quick on its heels.

19. She Became A Lost Girl

Kathleen putzed around America for a few years after her parents dragged her back, attending and then dropping out of school, writing for a few newspapers, and generally living the desultory existence of the rich and not-famous. Still, the life she had in England was never far from her mind, and she grew more and more restless. So restless, in fact, that she defied her parents in a way there was no going back from.

20. She Hatched A Plot

In 1943, something in Kathleen Kennedy broke for good. No longer willing to be her parents’ good little girl, she orchestrated a way back into England by signing up to work at an English Red Cross center for servicemen, risking her life once again to head into war-torn Europe while the conflict was still going on. It was one of the bravest things she ever did…but she may have had an ulterior motive.

21. She Had A Lost Love

When Kathleen returned to England, she met up with an old “friend” of hers, Billy Hartington, whom she had met at a dinner party during her first trip to England. Spoiler: They were more than just friends. On the face of it, though, he didn’t seem like the “one that got away” type. Hartington was reserved, quiet, and utterly opposite from the cheeky American socialite.

But Billy did have one trick up his sleeve to catch her.

22. She Met The Man Of Her Dreams

See, for all her rebellious ways, Kathleen was still used to money and the trappings that came with it, so she wasn’t at all unhappy when she found out that Billy Hartington was actually the fabulously wealthy William Hartington, future Duke of Devonshire and current Marquess of the ancestral estate. By these accounts, Billy and his old money should have fit right in with Kathleen’s family. That wasn’t what happened at all.

23. Her Family Hated Her Beau

Here was the rub when it came to Kathleen and Billy: While the Kennedys were still very much a strictly Irish Catholic family, Billy’s clan was old-school Protestant, and even in the more “modern” 1940s, neither brood wanted to see their child marry into the rival religion. Kathleen’s mother Rose in particular despised the match, and she made no secret of trying to split them up. It led to pure agony.

24. She Was In A Romeo And Juliet Story

As the months passed, Kathleen and Billy grew closer and closer, until they were both sure that each other was the one—except, that is, for the pesky religion problem. Kathleen tried to smooth things over constantly with her mother, who she still wanted to please and protect like when she was a child. As it turned out, though, it was Billy who dealt the killing blow.

25. Her Lover Made Her Choose

If Billy Hartington had unassuming and quiet manners on the outside, he certainly didn’t back down from this family feud. In fact, he gave Kathleen a terrible ultimatum. Eventually, he proposed to her like they had always talked about…but instead of giving her a fairy tale day, he insisted that she raise any children they had in the Protestant faith.

Some part of Kathleen would likely always regret her decision.

26. Her Mother Tried To Stop Her Wedding

In the end, Kathleen Kennedy said yes to her future Duke—and then her domineering mother went into overdrive. Rose had tried before to dissuade Kathleen from the relationship, but now she openly tried to mess up the wedding, actively separating Kathleen from Billy in the hopes that absence would make the heart grow colder. When it didn’t work, her tactics went from sneaky to scarring.

27. Her Family Snubbed Her On Her Wedding Day

Kathleen was stubborn and rebellious as ever, and she defiantly married her love on May 6, 1944. But it came at a heartbreaking cost. The civil ceremony was pleasingly simple and bare—but it was also bare of people. Only her eldest brother Joseph, who had managed to stay close with her, attended the wedding, while her mother and father stayed far away.

Still, Mama Rose Kennedy wasn’t content with absence as a punishment, and she made her displeasure known in another way.

28. Her Mother Was “Horrified” At Her Behavior

The Kennedy matriarch’s letters from around this time reveal the full extent of the family’s animosity and bitterness toward Kathleen’s chosen husband. In the aftermath of the proposal and the lead-up to the wedding, Rose Kennedy scrawled that she was not only “heartbroken” but “horrified” that Kathleen was marrying Billy. Well, thanks mom.

The “happiest day” of Kathleen’s life had turned into a tragic affair…and it ended up being a dark omen for things to come.

29. She Lost Her Brother In A Brutal Way

Just months after Kathleen tied the knot with her Romeo and became the “Marchioness of Hartington,” the bottom dropped out of her family. Her brother Joseph—the only one of her clan who had attended her wedding—was performing a confidential piloting mission in Europe when his plane exploded over the English channel, killing him near instantly.

The thing is, that was just the beginning of a series of unbelievable tragedies.

30. Her Husband Had To Abandon Her

Although Kathleen mourned her brother Joseph’s death, her marriage wasn’t on any safer ground. Mere weeks after she married Billy, he too was called to the front to fight in WWII on the continent. The newlyweds replaced a honeymoon with a long goodbye as Billy went off to France and then Belgium to face off against the Germans. This, too, had an awful ending.

31. She Was A War Bride

Kathleen and Billy felt their separation keenly, and Hartington often wrote to his wife of the goings on in the various theaters of war he was experiencing, and how it made him feel “so unworthy of it all living as I have in reasonable safety and comfort during these years.” At the same time, he missed her desperately, saying, “[I]long for you to be here.” Sadly, the lovers would never have a reunion.

32. She Went Through An Unimaginable Loss

Fresh off the pain of losing a family member, Kathleen was in for another horrific ordeal. In September 1944, less than a month after her brother Joseph died over the English Channel, she got word that her new husband Billy had also perished in combat at the age of 26. This would have been shocking news enough, but then details started coming in about how he died, and her blood must have run cold.

33. Her Husband Died Instantly

Kathleen’s marriage had never been completely happy, but her husband’s death was utterly tragic. The heir to the dukedom of Devonshire died violently and instantly after an enemy sniper shot him while he and the other men in his troop were trying to liberate a town in Belgium. Billy lost his life far away from his beloved, and the story got more bitter from there.

34. She Never Got To Say Goodbye To Her True Love

With chaos still raging on the continent, the army asked and received permission from Kathleen to bury Billy close by to where he first fell on that fateful day. Of course, Katheen wanted to prevent a difficult and dangerous journey back home with his body, so she truly never saw her husband again. Still, Kathleen may have thought she could close this tragic chapter of her life and move on. Fate laughed right in her face.

35. She Made A Sad Homecoming

Kathleen was a shell of her former self as she mourned Billy, and even went back to America for a time to take refuge in the chilly arms of her family. When this didn’t seem to make her feel better (I wonder why), Kathleen found herself right back in England, mad with grief but still young and red-blooded. As it turned out, it was the perfect recipe for disaster.

36. She Was On The Rebound

Now going under the esteemed name of “Lady Hartington” in honor of her fallen husband, Kathleen began hitting the town practically every night and displaying oodles of the charm and wit that had made her such a debutante darling in the pre-WWII years. She had gotten her fill of death, and she intended to live life to the fullest—including making some very bad decisions.

37. She Met A Scandalous Man

As part of her comeback tour, Kathleen met Peter Wentworth-Fitzwilliam, the 8th Earl of Fitzwilliam, who styled himself with the even loftier title of “Viscount Milton.” A solider himself and a dashing gentleman all around, it wasn’t long before Kathleen found herself under the Viscount’s spell, and they struck up an affair. But there was one enormous problem.

38. She Had A Married Lover

The Kennedys were all about public propriety, and there was absolutely nothing proper about Kathleen and the Viscount’s dalliance. The Viscount was currently trapped in an unhappy, loveless marriage with Olive Dorothea Plunket, whose alcoholism had torn them apart and helped push him into Kathleen’s arms. In other words, the Viscount had “TABLOID FODDER” written all over him. So you can imagine the Kennedys’ reaction…

39. Her Family Threatened To Disown Her

If Rose Kennedy was horrified at her daughter’s first husband, she was near fainting when she heard that Kathleen was running around in the shadows with a married and scandalous Viscount. But then she took it up a notch. The matriarch threatened that if things got serious this time around, Kathleen would almost certainly find herself as the black sheep of the family.

Maybe this “I’ll disown you” tactic worked on the other Kennedy children, but it had the exact wrong effect on Kathleen.

40. She Was Stubborn To A Fault

Instead of backing down from the Viscount, her mother’s threats only made Kathleen want to take him more seriously, especially when her lover started actively promising to marry her providing he could disengage himself from his pesky wife. That was enough for the romantic Kathleen, and she began hearing a second set of wedding bells in her head. If only she hadn’t.

41. Her Lover Was A Bad Man

For all that Kathleen was terrifically in love with her Viscount, the man had a sinister side. Oh sure, he was richer than Croesus—richer, even, than her first husband Billy Hartington—but the Viscount liked to throw both his weight and his money around, and was infamous around London as a heavy drinker and an obsessive gambler.

Oh, and did I mention he was Protestant too? More than that, Kathleen seemed to know the trouble she was in.

42. She Knew She Could Do Better

Viscount Milton certainly excited Kathleen, but she’d been around the block enough times to know a bad boy when she saw him, and she didn’t hide that knowledge. One of her nicknames for her married lover was “Rhett Butler,” after the toxic, uncaring lead of Gone With the Wind. Still, she couldn’t seem to get out of the relationship, and instead she tragically kept going full tilt ahead.

43. She Came Up With A Plan

While Kathleen’s mother was quite obviously diametrically opposed to this new match, Kathleen still held out hope that she could convince her father that the Viscount was marriage material—again, supposing the cad ever became officially single. So, in May 1948, when Kathleen got word that Joseph Kennedy Sr. was going to be in France on business, she hatched a doomed plan.

44. She Wanted To Be Daddy’s Little Girl

Kathleen knew she had charisma to spare, and hoped that if she could only meet her father in Paris with the Viscount in tow (natch), the Kennedy head of household would fall in love with her beau and give into his charming daughter’s wishes. On top of that, she and the Viscount could take a little vacation on the French Riviera as a bonus. I mean, what could go wrong?

45. She Took A Lover’s Holiday

On May 13, 1948, Kathleen and the Viscount flew from Paris to a holiday spot on the Riviera on the tiny, somewhat rickety de Havilland DH.104 Dove. Despite the humbleness of the craft, it was a cozy way for the lovers to spend a little time together, and as the flight took off at around 3:30 pm, everything seemed well. Until, that is, the plane went right into the eye of a storm.

46. She Entered Stormy Weather

An hour into the flight, just as the aircraft entered into stormy skies, the plane lost radio contact. We now know that the four people on the flight, including Kathleen and her Viscount, plus the pilot and the navigator, experienced an excruciating 20 minutes of intense turbulence, white-knuckling it through the air and holding on for dear life. But when they exited the clouds, it got deadly in an instant.

47. She Endured A Nightmare

It was out of the frying pan and into the fire for poor Kathleen, as the plane no sooner cleared the storm than everyone on board realized they were in a heart-stopping nosedive and about to crash. The pilot, still fighting to the bitter end, pulled up the plane to avoid impact, and succeeded for a few breathless seconds. But in the next moment, everything fell apart for good.

48. She Suffered Everyone’s Worst Fear

As it happened, the ravages of the turbulence and now the stress of the rapid change of direction was too much for the plane. The wind suddenly and quite literally ripped the plane apart. It tore off a wing, both engines, and then the tail of the aircraft. Kathleen, her beau, and the two other souls on board didn’t have a single chance of survival when the body of the plane finally crashed into the ground.

Kathleen Kennedy had finally succumbed to the Kennedy curse…but her tragedy was far from over.

49. Her Mother Insulted Her One Last Time

Sometimes tragedy can bring a family together, but not Kathleen’s family. In death, her mother dealt her the most brutal blow of all. Rose Kennedy didn’t attend her own daughter’s funeral, though. She checked herself into a hospital around the same time…perhaps, to cover the rudeness. Just as with her wedding day, only one of Kathleen’s family members, her father, watched her body go into the ground.

50. She Rests In Peace

True to her rebellious nature, Kathleen isn’t buried with her family, but rather with her husband Billy Hartington at St. Peter’s Churchyard in Edensor, where most of the old Dukes of Devonshire and their beloved relatives are buried. Fittingly for this firecracker of a woman, the inscription on her grave reads: “Joy she gave joy she has found.”

Sources: 1, 2, 3, 4, 5, 6, 7

Factinate Featured Logo Featured Article
My mom never told me how her best friend died. Years later, I was using her phone when I made an utterly chilling discovery.
The Truth Always Comes Out: Dark Family Secrets Exposed The Truth Always Comes Out: Dark Family Secrets Exposed
Factinate Featured Logo Featured Article
Madame de Pompadour was the alluring chief mistress of King Louis XV, but few people know her dark history—or the chilling secret shared by her and Louis.
Entrancing Facts About Madame de Pompadour, France's Most Powerful Mistress Entrancing Facts About Madame de Pompadour, France's Most Powerful Mistress
Factinate Featured Logo Featured Article
I tried to get my ex-wife served with divorce papers. I knew that she was going to take it badly, but I had no idea about the insane lengths she would go to just to get revenge and mess with my life.
These People Got Revenge In The Most Ingenious Ways These People Got Revenge In The Most Ingenious Ways
Factinate Featured Logo Featured Article
Catherine of Aragon is now infamous as King Henry VIII’s rejected queen—but few people know her even darker history.
Tragic Facts About Catherine of Aragon, Henry VIII’s First Wife Tragic Facts About Catherine of Aragon, Henry VIII’s First Wife


Dear reader,

Want to tell us to write facts on a topic? We’re always looking for your input! Please reach out to us to let us know what you’re interested in reading. Your suggestions can be as general or specific as you like, from “Life” to “Compact Cars and Trucks” to “A Subspecies of Capybara Called Hydrochoerus Isthmius.” We’ll get our writers on it because we want to create articles on the topics you’re interested in. Please submit feedback to contribute@factinate.com. Thanks for your time!

Do you question the accuracy of a fact you just read? At Factinate, we’re dedicated to getting things right. Our credibility is the turbo-charged engine of our success. We want our readers to trust us. Our editors are instructed to fact check thoroughly, including finding at least three references for each fact. However, despite our best efforts, we sometimes miss the mark. When we do, we depend on our loyal, helpful readers to point out how we can do better. Please let us know if a fact we’ve published is inaccurate (or even if you just suspect it’s inaccurate) by reaching out to us at contribute@factinate.com. Thanks for your help!

Warmest regards,

The Factinate team