Kathleen Cavendish, Marchioness of Hartington

Kathleen Agnes Cavendish, Marchioness of Hartington (' Kennedy; February 20, 1920 – May 13, 1948), also known as "Kick" Kennedy''', was an American socialite.

Kathleen Agnes Kennedy was born at home at 83 Beals Street in Brookline, Massachusetts on February 20, 1920, the fourth child and second daughter of Joseph P. Kennedy Sr. and Rose Fitzgerald.

She was nicknamed "Kick" because of her "irrepressible nature".

Kathleen was especially close to her older brother, John F. Kennedy, known as "Jack".

Her other siblings were Joseph Jr., Rosemary, Eunice, Patricia, Robert, Jean and Ted.

Kathleen was educated at Riverdale Country School in the Riverdale section of the Bronx, New York City.

Her two brothers, Robert and Joseph P. Jr. also went to the same school.

She also attended Noroton Convent of the Sacred Heart in Noroton, Connecticut, and the Holy Child Convent in Neuilly, France.

While the Kennedy daughters were not raised to have political ambitions like their brothers, they were nonetheless provided with many of the same educational and social opportunities, owing to their father's powerful financial and political connections and influence.

When her father was serving as U.S. Ambassador to the United Kingdom, Kathleen made many friends in London and was the "debutante of 1938".

This was particularly the case when President Franklin D. Roosevelt appointed Joseph as United States Ambassador to the United Kingdom in 1938.

As a child, Kathleen was very athletic and played football with her brothers.

An account cited that this stemmed from the ethos of competition that her father instilled on the young children.

They were split into teams and would compete in sports such as football in Hyannis Port.

Her optimism and high spirits attracted many suitors, some of whom were Jack's closest friends.

When Kathleen attended the Riverdale Country School, her mother did not approve of the male attention she attracted, and sent her to the all-girls Noroton Convent of the Sacred Heart.

Eventually, Kathleen started to date, and had her first serious relationship with, Peter Grace, an heir to W. R. Grace and Company.

Kathleen's time in Britain during her father's term as Ambassador dramatically influenced the remainder of her life.

While living in England, she was educated in London at Queen's College and quickly cultivated a wide circle of friends, both male and female, in British high society.

She dated David Rockefeller and was declared the "debutante of 1938" by the English media when she made her debut at the Queen Charlotte's Ball.

Following the German invasion of Poland and the outbreak of World War II in September 1939, Kick, who was staying at the family home in the south of France, had to rush to England with her friend Janey Kenyon Slaney.

The Kennedy family, to save Joseph and daughter Rosemary, returned to the United States.

Kathleen, having become very fond of England and the many friends she had made during her two years there, petitioned her parents to remain in London in spite of the coming danger.

However, she was overruled by her father, and sailed back home in the early fall of 1939.

After returning to the U.S., Kennedy enrolled at the Finch School for a time, and then attended Florida Commercial College.

In addition to her studies, she also began volunteering work for the American Red Cross.

In 1941, she decided to leave school, and began working as a research assistant for Frank Waldrop, the executive editor for the Washington Times-Herald.

She later teamed with Inga Arvad, who wrote the "Did You Happen to See....."

column, and was eventually given her own column where she reviewed films and plays.

In 1943, seeking a way to return to England, Kathleen signed up to work in a center for servicemen set up by the Red Cross.

During her time in England, both before and particularly during the war, she grew increasingly more independent from her family and the Roman Catholic Church to which they belonged.

During this time, Kennedy began a romantic relationship with politician William Cavendish, Marquess of Hartington (usually known to his family and friends as Billy Hartington).

Working with the Red Cross, she began a romantic relationship with Lord Hartington, whom she married in May 1944.

He was killed on active service in Belgium only four months later.

Kathleen died in a plane crash in 1948, flying to the south of France while on vacation with her new partner, the 8th Earl Fitzwilliam.

She was the second daughter of Joseph P. Kennedy Sr. and Rose Fitzgerald, a sister of U.S. President John F. Kennedy and Senators Robert F. Kennedy and Ted Kennedy, and the wife of the Marquess of Hartington, heir apparent to the 10th Duke of Devonshire.

He was the eldest son and heir apparent of the 10th Duke of Devonshire.

The two had met and begun a friendship when she moved to England when her father was appointed American Ambassador.

Despite objections from her mother, Kennedy and Lord Hartington reunited upon her return to England.

Rose especially rejected their relationship because she saw that their marriage would break the laws of the Roman Catholic Church by allowing Kathleen's children to be raised in the Church of England (Anglican Communion) rather than the Roman Catholic Church.