Question: Who is Sancha Of Castile, Queen Of Aragon's paternal grandmother?

Knowledge 1: Sancha of Castile, Queen of Aragon
Sancha of Castile (21 September 1154/5 – 9 November 1208) was the only surviving child of King Alfonso VII of Castile by his second wife, Richeza of Poland.On January 18, 1174, she married King Alfonso II of Aragon at Zaragoza; they had at least eight children who survived into adulthood.A patroness of troubadours such as Giraud de Calanson and Peire Raymond, the queen became involved in a legal dispute with her husband concerning properties which formed part of her dower estates.In 1177 she entered the county of Ribagorza and took forcible possession of various castles and fortresses which had belonged to the crown there.After her husband died at Perpignan in 1196, Sancha was relegated to the background of political affairs by her son Peter II.She retired from court, withdrawing to the Hospitaller convent for noble ladies, the Monastery of Santa María de Sigena, at Sigena, which she had founded.There she assumed the cross of the Order of St John of Jerusalem which she wore until the end of her life.The queen mother entertained her widowed daughter Constance at Sigena prior to her leaving Aragon to marry Emperor Frederick II in 1208.She died soon afterwards, aged fifty-four, and was interred in front of the high altar of her foundation at the Monastery of Santa María de Sigena; her tomb is still there to be seen. [SEP] Knowledge 2: Alfonso VII of León and Castile
Alfonso VII (1 March 110521 August 1157), called the Emperor ("el Emperador"), became the King of Galicia in 1111 and King of León and Castile in 1126.Alfonso, born Alfonso Raimúndez, first used the title Emperor of All Spain, alongside his mother Urraca, once she vested him with the direct rule of Toledo in 1116.Alfonso later held another investiture in 1135 in a grand ceremony reasserting his claims to the imperial title.He was the son of Urraca of León and Raymond of Burgundy, the first of the House of Ivrea to rule in the Iberian peninsula.Alfonso was a dignified and somewhat enigmatic figure.His rule was characterised by the renewed supremacy of the western kingdoms of Christian Iberia over the eastern (Navarre and Aragón) after the reign of Alfonso the Battler.Though he sought to make the imperial title meaningful in practice to both Christian and Muslim populations, his hegemonic intentions never saw fruition.During his tenure, Portugal became "de facto" independent, in 1128, and was recognized as "de jure" independent, in 1143.He was a patron of poets, including, probably, the troubadour Marcabru.
Knowledge 1: Alfonso VII of León and Castile
Alfonso VII (1 March 110521 August 1157), called the Emperor ("el Emperador"), became the King of Galicia in 1111 and King of León and Castile in 1126.Alfonso, born Alfonso Raimúndez, first used the title Emperor of All Spain, alongside his mother Urraca, once she vested him with the direct rule of Toledo in 1116.Alfonso later held another investiture in 1135 in a grand ceremony reasserting his claims to the imperial title.He was the son of Urraca of León and Raymond of Burgundy, the first of the House of Ivrea to rule in the Iberian peninsula.Alfonso was a dignified and somewhat enigmatic figure.His rule was characterised by the renewed supremacy of the western kingdoms of Christian Iberia over the eastern (Navarre and Aragón) after the reign of Alfonso the Battler.Though he sought to make the imperial title meaningful in practice to both Christian and Muslim populations, his hegemonic intentions never saw fruition.During his tenure, Portugal became "de facto" independent, in 1128, and was recognized as "de jure" independent, in 1143.He was a patron of poets, including, probably, the troubadour Marcabru. [SEP] Knowledge 2: Maria of Aragon, Queen of Castile
Maria of Aragon was the Queen consort of Castile and Leon as the wife of John II of Castile.She was the daughter of Ferdinand I of Aragon and Eleanor of Alburquerque.
Knowledge 1: Sancha of Castile, Queen of Aragon
Sancha of Castile (21 September 1154/5 – 9 November 1208) was the only surviving child of King Alfonso VII of Castile by his second wife, Richeza of Poland.On January 18, 1174, she married King Alfonso II of Aragon at Zaragoza; they had at least eight children who survived into adulthood.A patroness of troubadours such as Giraud de Calanson and Peire Raymond, the queen became involved in a legal dispute with her husband concerning properties which formed part of her dower estates.In 1177 she entered the county of Ribagorza and took forcible possession of various castles and fortresses which had belonged to the crown there.After her husband died at Perpignan in 1196, Sancha was relegated to the background of political affairs by her son Peter II.She retired from court, withdrawing to the Hospitaller convent for noble ladies, the Monastery of Santa María de Sigena, at Sigena, which she had founded.There she assumed the cross of the Order of St John of Jerusalem which she wore until the end of her life.The queen mother entertained her widowed daughter Constance at Sigena prior to her leaving Aragon to marry Emperor Frederick II in 1208.She died soon afterwards, aged fifty-four, and was interred in front of the high altar of her foundation at the Monastery of Santa María de Sigena; her tomb is still there to be seen. [SEP] Knowledge 2: Maria of Aragon, Queen of Castile
Maria of Aragon was the Queen consort of Castile and Leon as the wife of John II of Castile.She was the daughter of Ferdinand I of Aragon and Eleanor of Alburquerque.

Answer: Urraca of León