Question: Who is Kathleen Cavendish, Marchioness Of Hartington's maternal grandfather?

Knowledge 1: Kathleen Cavendish, Marchioness of Hartington
Kathleen Agnes Cavendish, Marchioness of Hartington ("née" Kennedy; February 20, 1920 – May 13, 1948), also known as "Kick" Kennedy, was an American socialite.She was the daughter of Joseph P. Kennedy, Sr.and Rose Kennedy, sister of future U.S. President John F. Kennedy, and wife of the Marquess of Hartington, heir apparent to the 10th Duke of Devonshire.When her father was serving as United States Ambassador to the United Kingdom, Kathleen made many friends in London and was the "debutante of 1938." 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.Kick died in a plane crash in 1948, flying to the south of France while on vacation with her new partner, the 8th Earl Fitzwilliam. [SEP] Knowledge 2: Rose Kennedy
Rose Elizabeth Fitzgerald Kennedy, Countess of the Holy Roman Church(July 22, 1890 – January 22, 1995) was an American philanthropist, socialite, and the matriarch of the Kennedy family.She was deeply embedded in the "lace curtain" Irish Catholic community in Boston, where her father John F. Fitzgerald was mayor.Kennedy was the wife of businessman and investor Joseph P. Kennedy Sr., who was United States Ambassador to the United Kingdom, formally known as Ambassador to the Court of St. James's in the UK.Their nine children included President John F. Kennedy, Senator Robert F. Kennedy, and longtime Senator Ted Kennedy.In 1951 she was ennobled by Pope Pius XII, becoming the sixth American woman to be granted the rank of Papal countess.
Knowledge 1: Kathleen Cavendish, Marchioness of Hartington
Kathleen Agnes Cavendish, Marchioness of Hartington ("née" Kennedy; February 20, 1920 – May 13, 1948), also known as "Kick" Kennedy, was an American socialite.She was the daughter of Joseph P. Kennedy, Sr.and Rose Kennedy, sister of future U.S. President John F. Kennedy, and wife of the Marquess of Hartington, heir apparent to the 10th Duke of Devonshire.When her father was serving as United States Ambassador to the United Kingdom, Kathleen made many friends in London and was the "debutante of 1938." 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.Kick died in a plane crash in 1948, flying to the south of France while on vacation with her new partner, the 8th Earl Fitzwilliam. [SEP] Knowledge 2: Kaya Alp
Kaya Alp was, according to Ottoman tradition, the son of Kızıl Buğa and the father of Suleyman Shah, who was, in turn, the grandfather of Ertuğrul, and the great grandfather of the Ottoman Empire founder, Osman I.
Knowledge 1: Kathleen Cavendish, Marchioness of Hartington
Kathleen Agnes Cavendish, Marchioness of Hartington ("née" Kennedy; February 20, 1920 – May 13, 1948), also known as "Kick" Kennedy, was an American socialite.She was the daughter of Joseph P. Kennedy, Sr.and Rose Kennedy, sister of future U.S. President John F. Kennedy, and wife of the Marquess of Hartington, heir apparent to the 10th Duke of Devonshire.When her father was serving as United States Ambassador to the United Kingdom, Kathleen made many friends in London and was the "debutante of 1938." 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.Kick died in a plane crash in 1948, flying to the south of France while on vacation with her new partner, the 8th Earl Fitzwilliam. [SEP] Knowledge 2: Charlotte Cavendish, Marchioness of Hartington
Charlotte Elizabeth Cavendish, Marchioness of Hartington, 6th Baroness Clifford ("née" Boyle; 27 October 1731 – 8 December 1754) was the daughter of Richard Boyle, 3rd Earl of Burlington and Lady Dorothy Savile.From 1748 until her death she was married to William Cavendish, Marquess of Hartington, later the 4th Duke of Devonshire and Prime Minister of Great Britain.

Answer: John F. Fitzgerald