Macrina the Elder
Macrina the Elder( before AD 270 –) was the mother of Basil the Elder, and the grandmother of Basil the Great, Gregory of Nyssa, Peter of Sebaste, and Macrina the Younger.
Teresa Lourenço
Teresa Gille Lourenço( Lisbon, 1330 –?), was the lover of King Peter I of Portugal and mother of King John I of Portugal.
Beatrice, Countess of Alburquerque
Beatrice of Portugal was Countess of Alburquerque as the wife of Sancho Alfonso of Alburquerque.
She was the daughter of Peter I of Portugal and his wife Inês de Castro.
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.
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.
Afonso IV of Portugal
Afonso IV (8 February 129128 May 1357), called the Brave , was King of Portugal from 1325 until his death.
He was the only legitimate son of King Denis of Portugal by his wife Elizabeth of Aragon.
Hannah Arnold
Hannah Arnold, also known as Hannah Waterman King, was the grandmother of Benedict Arnolds children.
Peter I of Portugal
Peter I (Portuguese: "
Pedro I" (8 April 1320 – 18 January 1367), called the Just or the Cruel
(Portuguese: "o JustoO Cruel"), was King of Portugal from 1357 until his death.
He was the third but only surviving son of Afonso IV of Portugal and his wife, Beatrice of Castile.
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.

Question: Who is the paternal grandmother of Peter I Of Portugal?
Answer: Elizabeth of Aragon