Question: Who is Princess Shōshi (1027–1105)'s maternal grandfather?
Sentence (from "Fujiwara no Ishi"): In 1018, at the age of nineteen, she married her ten-year-old nephew the Emperor and became Empress ("Chugu"), and thus the third of her sisters to become Empresses in succession, all in marriages arranged by their father the regent.
Relevant evidence: No