Bhanurangsi Savangwongse
Bhanurangsi Savangwongse, the Prince Bhanubandhu Vongsevoradej (11 January 1859 – 13 June 1928)  was a son of HM King Mongkut of Siam and HM Queen Debsirindra.
Although the Prince held a number of posts in the government of his elder brother, King Chulalongkorn, including the post of Commander-in-Chief of the Royal Siamese Army, he is best remembered as the founder of the Thai postal service.
He was the best known as founder of the Thai postal service.
and the first Field marshal in Royal Siamese Army during King Vajiravudh.
His most famous son is the Formula One racer, Prince Birabongse Bhanutej Bhanubandh, better known as Prince Bira.
Dibyasambandh
Princess Dibyasambanna (Née Her Serene Highness Princess (Mom Chao)
Dibyasambanna Bhanubandh
; ; 17 May 1885 - 26 July 1908) was a Princess of Siam (later Thailand).
She was a member of Siamese royal family, specifically the Bhanubandh family, as a daughter of Prince Bhanurangsi Savangwongse and Mom Liam.
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.
Hannah Arnold
Hannah Arnold, also known as Hannah Waterman King, was the grandmother of Benedict Arnolds children.
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.
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.
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.
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.

Question: Who is Dibyasambandh's paternal grandmother?
Answer: Debsirindra