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.
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.
Peter, Duke of Coimbra
Infante D. Pedro, Duke of Coimbra , (9 December 1392 – 20 May 1449) was a Portuguese "infante" (prince) of the House of Aviz, son of King John I of Portugal and his wife Philippa of Lancaster, daughter of John of Gaunt.
In Portugal, he is better known as Infante D. Pedro das Sete Partidas [do Mundo], "of the Seven Parts [of the World]" because of his travels.
Possibly the best-travelled prince of his time
, he was regent between 1439 and 1448.
He was also 1st
Lord of Montemor-o-Velho, Aveiro, Tentúgal, Cernache, Pereira, Condeixa and Lousã.
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.
John, Constable of Portugal
Infante John, Constable of Portugal( 13 January 1400 – 18 October 1442) was a Portuguese" infante"( prince) of the House of Aviz, Constable of Portugal and master of the Portuguese Order of St. James( Santiago).
In Portugal, he is commonly referred to as the" O Infante Condestávelthe Constable Prince").
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.
Hannah Arnold
Hannah Arnold, also known as Hannah Waterman King, was the grandmother of Benedict Arnolds children.
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.
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.
Peter, Constable of Portugal
Peter of Coimbra (also known as Peter the Constable)
(pronounced ; c. 1429 – Granollers, 30 June 1466)
was the son of Infante Peter, Duke of Coimbra, who became the fifth Constable of Portugal and third Grand Master of the Order of Saint Benedict of Aviz.
The Consell de Cent later granted Peter the crown of Aragon, which he claimed from 1463 to 1466 in opposition to John II.
Sometimes called Peter V, his status as king of Aragon, however, along with that of John II's other challengers, is disputed.

Question: Who is the paternal grandmother of Peter, Constable Of Portugal?
Answer: Philippa of Lancaster