Hannah Arnold
Hannah Arnold, also known as Hannah Waterman King, was the grandmother of Benedict Arnolds children.
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.
Constance of York, Countess of Gloucester
Constance of York, Countess of Gloucester( – 28 November 1416) was the only daughter of Edmund of Langley, 1st Duke of York and his wife Isabella of Castile, daughter of King Peter of Castile and his favourite mistress, María de Padilla.
Constance of Castile
Constance of Castile (1136 or 1140 - 4 October 1160) was Queen of France as the second wife of Louis VII, who married her following the annulment of his marriage to Eleanor of Aquitaine.
She was a daughter of Alfonso VII of León and Berengaria of Barcelona, but her year of birth is not known.
Berengaria of Barcelona
Berengaria of Barcelona (1116 – January 15, 1149), called in Spanish Berenguela de Barcelona, was Queen consort of Castile, León and Galicia.
She was the daughter of Ramon Berenguer III, Count of Barcelona, and Douce I, Countess of Provence.
On November 10/17 1128 in Saldaña, Berengaria married Alfonso VII, King of Castile, León and Galicia.
Their children were:
She died in Palencia, and was buried at the Cathedral of Santiago de Compostela.
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.
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.
Constance of Arles
Constance of Arles( c. 986 – 28 July 1032), also known as Constance of Provence, was queen of France as the third spouse of King Robert II of France.
Catherine of Lancaster
Catherine of Lancaster (Castilian: "Catalina"; 31 March 1373 – 2 June 1418) was Queen of Castile by marriage to King Henry III of Castile.
She governed Castile as regent from 1406 until 1418 during the minority of her son.
Queen Catherine was the daughter of John of Gaunt, 1st Duke of Lancaster, and his second wife, Constance of Castile (the daughter and heir of King Peter of Castile, who died at the hands of his half brother Henry II).
She was born in Hertford Castle, her father's chief country home, on 31 March 1373.
Catherine became Queen of Castile through her marriage to Henry III.

Question: Who is Constance Of Castile's maternal grandmother?
Answer: Douce I, Countess of Provence