Details About Kathleen Kennedy And Billy Hartington's Tragic, Short-Lived Romance

A bold, outspoken American woman travels to London with her family at 18 and falls for a reserved British duke-to-be. It sounds like the plot of a period romance but, in reality, it was yet another example of the complex, extraordinary lives and, unfortunately, the tragedy surrounding the Kennedy family. In this case, the brash woman was the fourth Kennedy child and younger sister to former President John F. Kennedy, Kathleen Kennedy, nicknamed Kick. 

JFK's little sister lived up to her nickname with her brazen ferocity and unbridled sense of humor, which shocked the British aristocrats she encountered due to her father's appointment as the U.S. ambassador to Great Britain. However, it was this unapologetic confidence that caused William Cavendish, the Marquess of Hartington and duke-to-be (known as Billy Hartington), to fall for and, eventually, propose to Kennedy.

But, as was often the case in the Kennedy family, this brief romance would end in tragedy only six years after it started.

Kathleen Kennedy and Billy Hartington met at a garden party in July 1938 and instantly sparked a kindred friendship. However, the two would be forced to separate after Great Britain declared war on Germany in 1939, causing the Kennedy family to move back to the States. Emboldened by her eagerness to return to England and her duty to the war effort, Kennedy joined the American Red Cross and flew back to a war-ravaged London in 1943. 

Upon her return to London, Kennedy and Hartington's friendship picked up where they had left it, soon deepening into a romantic courtship. Hartington's mother invited Kennedy to Christmas, and soon after, Hartigto proposed. The couple wed in an unassuming civil ceremony in the Caxton Hall Registry Office on May 6, 1944. Four months later, WWII would forever alter their lives. 

Billy was called to service as a member of the British army on June 13, 1944. On September 9, the Marquess of Hartington was killed in action while fighting German forces in Belgium, ending the young couple's future together. And, although the war would prove to be the most insurmountable challenge the couple faced, it wasn't the only one.

Supposing Billy Hartington had survived his time in the war, one could assume their romance would've been bogged down with conflict nonetheless. The Marquess of Hartington was raised Protestant in the Church of England, while Kathleen Kennedy was the daughter of a staunchly Catholic family — something that her family struggled to reconcile during and after her marriage.

According to the 2016 biography "Kick Kennedy: The Charmed Life and Tragic Death of the Favorite Kennedy Daughter" by Barbara Leaming (via People), Kennedy's mother, Rose, said she was "horrified" and "heartbroken" by the marriage. When Kennedy fell into an affair with another British Protestant, Earl Peter Wentworth-Fitzwilliam, two years after Hartington's death, the fissure between Kennedy and her mother deepened. Sadly, this relationship was never mended before Kennedy died in a plane crash while flying from London to Paris in 1948. 

Kennedy's premature death came over a decade before her older brother would become the 35th President of the United States and seven years after a failed lobotomy would permanently color the tragic story of JFK's other sister, Rosemary. Leaming wrote that Kick Kennedy was the "star of the family, and it left them, particularly her mother, with terrible, unresolved agony. Her mother was left with something that was so unresolved — that she didn't go to her daughter's funeral."