Diana Guardato
Diana Guardato was a member of the aristocratic Patrician Guardato family, and had three children with King Ferdinand I: Diana Guardato is the 16th- Great Grandmother of His Royal Highness Albert II of Belgium, 15th- Great Grandmother of His Majesty Juan Carlos
I of Spain, 17th- Great Grandmother of Philippe of Belgium, 14th- Great Grandmother of His Majesty Manuel II of Portugal, 16th- Great Grandmother of Grand Duke Henri, as well as many others.
Kaoru Hatoyama
After the elections of 2009, she became more widely known as the grandmother of Prime Minister Yukio Hatoyama and his politician brother Kunio Hatoyama.
Purnima (Hindi actress)
Purnima Das Verma( born Meherbhano Mohammad Ali) was an Indian film actress who worked predominantly in Hindi language films.
She is the grandmother of actor Emraan Hashmi.
Hannah Arnold
Hannah Arnold, also known as Hannah Waterman King, was the grandmother of Benedict Arnolds children.
Oona O'Neill
Oona O'Neill Chaplin, Lady Chaplin (14 May 1925 – 27 September 1991) was an actress who became a British citizen after renouncing her American citizenship.
She was the daughter of American playwright Eugene O'Neill and English-born writer Agnes Boulton, and the fourth and last wife of English actor and filmmaker Charlie Chaplin.
O'Neill's parents divorced when she was four years old, after which she was raised by her mother in Point Pleasant, New Jersey, and rarely saw her father.
She first came to the public eye during her time at the Brearley School in New York City between 1940 and 1942, when she was photographed attending fashionable nightclubs with her friends Carol Marcus and Gloria Vanderbilt.
In 1942, she received a large amount of media attention after she was chosen as "The Number One Debutante" of the 1942–1943 season at the Stork Club.
Soon after, she decided to pursue a career in acting and, after small roles in two stage productions, headed for Hollywood.
In Hollywood, O'Neill was introduced to Chaplin, who considered her for a film role.
The film was never made, but O'Neill and Chaplin began a romantic relationship and married in June 1943, a month after she had turned 18.
The 36-year age gap between them caused a scandal, and severed O'Neill's relationship with her father, who was only six months older than Chaplin and who had already strongly disapproved of her wish to become an actress.
Following the marriage, O'Neill gave up her career plans.
She and Chaplin had eight children together and remained married until his death in 1977.
The first decade of their marriage was spent living in Beverly Hills, but after Chaplin's re-entry permit to the United States was cancelled during a voyage to London in 1952, they moved to Manoir de Ban in the Swiss village of Corsier-sur-Vevey.
In 1954, O'Neill renounced her US citizenship and became a British citizen.
Following Chaplin's death, she split her time between Switzerland and New York.
She died of pancreatic cancer at the age of 66 in Corsier-sur-Vevey in 1991.
Her daughter Geraldine Chaplin named her own daughter after Oona in 1986.
Tjuyu
Tjuyu( sometimes transliterated as Thuya or Thuyu) was an Egyptian noblewoman and the mother of queen Tiye, and the wife of Yuya.
She is the grandmother of Akhenaten, and great grandmother of Tutankhamun.
Hubba bint Hulail
Hubba bint Hulail was the grandmother of Hashim ibn' Abd Manaf, thus the great- great- great- grandmother of the Islamic" Nabī"( Prophet) Muhammad ibn Abdullah.
Anne Denman
Anne Denman( 1587–1661) was born in Olde Hall, Retford, Nottinghamshire.
Through a fortunate second marriage with Thomas Aylesbury, she became the grandmother of Lady Anne Hyde, Duchess of York and great- grandmother of Queen Mary II and Queen Anne.
Mona Hopton Bell
Mona Hopton Bell( 1867- 1940) was a British artist, best known for her portraits of civic figures.
She was the grandmother of the painter Jean H. Bell.
Christopher Chaplin
Christopher James Chaplin (born 8 July 1962) is a Swiss-born English composer and actor.
He is the youngest son of film comedian Charlie Chaplin and his fourth wife, Oona O'Neill.

Question: Who is Christopher Chaplin's maternal grandmother?
Answer: Agnes Boulton