She's the "unknown Kennedy" whose older brother became a U.S. president: Nov. 22, 2008, marks the 45th anniversary of John F. Kennedy's assassination. And this year is the 60th anniversary of Kathleen Kennedy's death, at 28.

Many Americans are familiar with the tragic story of the Kennedys. But few know much about Kathleen, who snagged a wealthy, titled British aristocratic. He was William Cavendish, the Marquess of Hartington — the powerful 10th Duke of Devonshire's son and heir not only to the title, but to the palatial Chatsworth House estate, among other rich properties. He was such a catch that the British royal family apparently had their eye on him for their own Princess Elizabeth, the future queen.

Kathleen, nicknamed "Kick," married Billy, as he was called, when she was 24, on May 6, 1944. A World War II romance, they were very much in love-despite their different faiths, which raised great conflict within their families: His family, for hundreds of generations, was very much Church of England, and hers was devout Roman Catholic. In fact, Rose Kennedy noted that she was "disturbed, horrified, heartbroken" that her daughter Kathleen had married a Protestant — and in a civil ceremony at that (Kathleen's brother, Joseph, was the only family member to attend). Rose didn't have contact with her for nearly two months after the wedding.

It was a sad, romantic tale: The young couple were together only five weeks before Billy's Coldstream Guards regiment was ordered to France. Three months later he was fatally shot in Belgium, just a month after Joseph Jr., the oldest Kennedy brother, was killed in a military plane crash.

Kathleen had first come to London in 1938 with her charismatic clan as a vivacious teenager. Her father Joseph had been appointed U.S. ambassador to the Court of St. James's. She quickly wowed British society, becoming one of its top debutantes.

"She was not beautiful, but her vitality and charm were such that she was the one who drew attention in a crowd," wrote the 11th Duchess of Devonshire, Billy's sister-in-law Deborah — now 88 and known as Her Grace The Dowager Duchess — in her fascinating book "Chatsworth: The House." "Her high spirits, funny American turn of phrase, so like her brother Jack's, and extreme good nature made her far more attractive than most pale English beauties. She was loved by everyone who knew her."

Following the shocking death of both her beloved brother and husband within a month, a grieving Lady Kathleen — after spending some time at Chatsworth House in Derbyshire with Billy's consoling family — decided to return to London, where she bought a townhouse. While volunteering at a Red Cross fundraising dance in June 1946, she met a dashing man — another wealthy British aristocrat named Peter Fitzwilliam, the 8th Earl Fitzwilliam, whose family seat was Wentworth House, an amazing "palace" in South Yorkshire, with a room for each day of the year. He was also Protestant and, even worse, still married (separated from his wife) with an 11-year-old daughter. (Two fascinating books give much detail about Kathleen's life: "Kathleen Kennedy" by Lynne McTaggart and "Black Diamonds" by Catherine Bailey.) It was nearly love at first sight for the couple.

But theirs was not a happy ending, either. Reportedly on their way to a romantic getaway in the South of France in May 1948 (before planning to meet Joseph Kennedy in Paris to discuss their desire to wed), their small, chartered plane crashed in stormy weather, instantly killing them. The Kennedy patriarch was the only family member to attend Lady Kathleen's London funeral Mass and later burial in a tiny graveyard at St. Peter's Church in Edensor, near Chatsworth House.

What an irony that, as ambitious as Joseph Sr. was for his children — aspiring for them to achieve great success in politics and other professional and social endeavors, even grooming his eldest son to be U.S. president some day —that Kathleen had become the Marchioness of Hartington upon marrying into one of England's oldest, most distinguished, and wealthiest families. But that apparently was not enough, becausethey were Protestant. (How times have changed with the subsequent generations.)

Today, visitors can see the tiny Protestant churchyard in the charming village where Kathleen is buried in the Cavendish family plot, with a plaque by her gravestone noting the June 1963 visit of JFK just months before his own death. And, about a mile away, is Chatsworth House, the gorgeous 297-room estate where, prior to her marriage, Kathleen had celebrated her 24th birthday. Each year, some half-million visitors each tour Chatsworth House, which for nearly five centuries has been the Cavendish family home. Currently, the 12th Duke and Duchess of Devonshire and their family reside there.

The Chatsworth House you see today is mostly rebuilt (and it was later expanded during the 19th century by the "Bachelor Duke") on the original footprint that, back in 1552, had been the dream of the ambitious Bess of Hardwick, mother of eight, who inherited wealth from her four marriages. She was said to be the most powerful woman in England after the queen. This year marks the 400th anniversary of her death.

"There is no theme, no connecting style," wrote the Dowager Duchess in her book of this massive estate. "Each room is a jumble of old and new, English and foreign, thrown together by generations of acquisitive inhabitants."

But the elegant rooms — including the entry, the breathtaking Painted Hall and its dramatic staircase — as well as the priceless artwork, china, tapestries and furnishings, including the throne chairs and footstools made for the coronation of King George III and Queen Charlotte, are amazing. The library has nearly 50,000 volumes, one of the finest private collections, which visiting scholars may use.

It was here at Chatsworth where Mary, Queen of Scots spent some time as a prisoner of Queen Elizabeth I; where King George V and Queen May stayed — as well as King Edward VII. It was also here in the Great Dining Room where, in 1832, a young Princess Victoria — who would become the renowned queen — visited for a few days with her mother, experiencing her first formal, adult dinner when she was 13.

And Chatsworth has been the site of several films, including "Pride and Prejudice" in 2005. Most recently, its chapel and gardens were used for the upcoming movie "The Duchess" — scheduled to be released Sept. 5 — about the life of the colorful Georgiana Cavendish, 5th Duchess of Devonshire and an ancestor of Diana, Princess of Wales. It stars Keira Knightley and Ralph Fiennes. Chatsworth will soon open a permanent exhibition on this duchess.

But what got my attention on the day that I toured Chatsworth — following an earlier visit that morning to Lady Kathleen Kennedy's gravesite — was a photograph in the portrait gallery. There, near a bust of Queen Elizabeth II — among all the huge, color portraits of Cavendish ancestors and other British aristocracy — hangs a modest black-and-white photo of a young, smiling Kathleen wearing her Red Cross uniform.

"Her charm comes through," writes the Dowager Duchess of the photo, "and you can see why she was the most popular girl of my generation."

IF YOU GO

Chatsworth House www.chatsworth.org

VisitBritain www.visitbritain.com

BritRail www.britrail.com

Sharon Whitley Larsen is a freelance travel writer. To find out more about Sharon Whitley Larsen and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.

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