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.
Mattias de' Medici
Mattias de' Medici (9 May 1613 – 11 October 1667) was the third son of Grand Duke Cosimo II de' Medici of Tuscany and Archduchess Maria Maddalena of Austria.
He was governor of Siena, with interruptions, from 1629.
He never married.
Archduchess Maria Maddalena of Austria
Maria Maddalena of Austria (Maria Magdalena; 7 October 1589 – 1 November 1631) was Grand Duchess of Tuscany from the accession of her husband, Cosimo II, in 1609 until his death in 1621.
With him, she had eight children, including a duchess of Parma, a grand duke of Tuscany, and an archduchess of Further Austria.
Born in Graz, she was the youngest daughter of Charles II, Archduke of Inner Austria, and his wife Maria Anna of Bavaria.
During the minority of her son, Grand Duke Ferdinando, she and her mother-in-law acted as regents from 1621 to 1628.
She died on 1 November 1631 in Passau.
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.
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.
Giovanni di Bicci de' Medici
Giovanni di Bicci de' Medici( c. 1360 – February 1429) was an Italian banker and founder of the Medici Bank.
While other members of the Medici family, such as Chiarissimo di Giambuono de' Medici, who served in the Signoria of Florence in 1201, and Salvestro de' Medici, who was implicated in the Ciompi Revolt of 1378, are of historical interest, it was Giovanni's founding of the family bank that truly initiated the family's rise to power in Florence.
He was the father of Cosimo de' Medici and Lorenzo de' Medici, and an ancestor of other notable Medici rulers.
For example, he was the grandfather of Piero di Cosimo de' Medici; the great- grandfather of Lorenzo de' Medici( the Magnificent); and the great- great- great- grandfather of Cosimo I de' Medici, Grand Duke of Tuscany.
Hannah Arnold
Hannah Arnold, also known as Hannah Waterman King, was the grandmother of Benedict Arnolds children.
Nannina de' Medici
Nannina de' Medici( 14 February 1448 – 14 May 1493), born Lucrezia de' Medici, was the second daughter of Piero di Cosimo de' Medici and Lucrezia Tornabuoni.
She was thus the elder sister of Lorenzo de' Medici.
She married Bernardo Rucellai.
Her father's name was Piero, so she is sometimes known as Lucrezia di Piero de' Medici.
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.

Question: Who is the maternal grandmother of Mattias De' Medici?
Answer: Maria Anna of Bavaria