Question: Who is Hawise, Duchess Of Brittany's maternal grandfather?

Knowledge 1: Hawise, Duchess of Brittany
Hawise of Rennes  (1037 – 19 August 1072) was sovereign Duchess of Brittany from 1066 until her death.She was the second child and heiress of Alan III, Duke of Brittany, by his wife, Bertha of Blois, and as such, a member of the House of Rennes.Hawise succeeded her older brother, Conan II, who was assassinated by poisoning on 11 December 1066.Little is known of the life of Hawise of Rennes.She was married to Hoel of Cornwall some time before 1058.Hoel exercised authority "jure uxoris" and continued to control the government after her death in 1072 acting as regent for their son, Alan IV.A second son, Matthew, inherited the county of Nantes. [SEP] Knowledge 2: Bertha of Blois
Bertha of Blois (French: "Berthe de Blois"; c. 1005 — c. 1080), was a Duchess consort of Brittany and a countess consort of Maine, married in 1018 to Alain III, Duke of Brittany, and in 1046 to Hugh IV, Count of Maine.She was the daughter of Odo II, Count of Blois and Ermengarde of Auvergne.
Knowledge 1: Hawise, Duchess of Brittany
Hawise of Rennes  (1037 – 19 August 1072) was sovereign Duchess of Brittany from 1066 until her death.She was the second child and heiress of Alan III, Duke of Brittany, by his wife, Bertha of Blois, and as such, a member of the House of Rennes.Hawise succeeded her older brother, Conan II, who was assassinated by poisoning on 11 December 1066.Little is known of the life of Hawise of Rennes.She was married to Hoel of Cornwall some time before 1058.Hoel exercised authority "jure uxoris" and continued to control the government after her death in 1072 acting as regent for their son, Alan IV.A second son, Matthew, inherited the county of Nantes. [SEP] Knowledge 2: Hoël II, Duke of Brittany
Hoël II( c. 1031–1084) was Count of Kernev(" French: Cornouaille Breton: Kernev"), from 1058 as Hoël V.On the basis of his marriage to Hawise, Duchess of Brittany, in 1066, he became Duke of Brittany" jure uxoris".Hoël was the son of Alan of Cornwall and his wife, Judith of Nantes, granddaughter of the illegitimate son of Alan II of Brittany.Hoël started the House of Kernev( Cornouaille) of Brittany, which ruled the Duchy until 1156.Little is known of the lives of Hawise and Hoël.However, this political marriage between the House of Rennes in the east and the House of Cornouaille in the west may have further strengthened Brittany at a time when external interference was attempted by William the Conqueror.After Hawise's death in 1072, Hoël acted as regent for his son, Alan IV, until the latter reached his majority in 1084.During his reign he faced several rebellions from Breton nobles.Geoffrey Grenonat of Rennes( a natural son of Duke Alan III of Brittany and thus a half- brother of Hawise) led a revolt and was joined by Ralph de Gael who had returned to Brittany from England after the failure of the previous year's Revolt of the Earls.In 1076, Ralph having plotted against Hoël, was besieged at Dol. William the Conqueror came to Hoël's aid, after which Hoël finally made peace with Ralph.Hoël's second son, Matthew, succeeded to the county of Nantes.
Knowledge 1: Hawise, Duchess of Brittany
Hawise of Rennes  (1037 – 19 August 1072) was sovereign Duchess of Brittany from 1066 until her death.She was the second child and heiress of Alan III, Duke of Brittany, by his wife, Bertha of Blois, and as such, a member of the House of Rennes.Hawise succeeded her older brother, Conan II, who was assassinated by poisoning on 11 December 1066.Little is known of the life of Hawise of Rennes.She was married to Hoel of Cornwall some time before 1058.Hoel exercised authority "jure uxoris" and continued to control the government after her death in 1072 acting as regent for their son, Alan IV.A second son, Matthew, inherited the county of Nantes. [SEP] Knowledge 2: Margaret of France, Duchess of Berry
Margaret of France, Duchess of Berry (French: "Marguerite de Valois")(5 June 1523 – 15 September 1574) was the daughter of King Francis I of France and Claude, Duchess of Brittany.

Answer: Odo II, Count of Blois