Casimir I of Opole
Casimir I of Opole( – 13 May 1230), a member of the Piast dynasty, was a Silesian duke of Opole and Racibórz from 1211 until his death.
Margareta of Opole
Margareta of Opole (– 15 January 1454), was a Polish princess.
She was a member of the Opole branch of House of Piast and by marriage a Duchess of Oława-Lubin-Chojnów.
She was the daughter of Duke Bolko IV of Opole, by his wife Margareta, possibly a member of the House of Görz.
Margareta of Toszek
Margareta of Toszek( 1467/68 – 8 November 1531), was a Polish princess and abbess.
Viola, Duchess of Opole
Viola, Duchess of Opole, also known as Veleslava,;( died 7 September 1251) was a Duchess consort of Opole- Racibórz through her marriage to Casimir I.
Bolko IV of Opole
Bolko IV of Opole (1363/67 – 6 May 1437), was a Duke of Strzelce and Niemodlin during 1382–1400 (with his brothers as co-rulers), Duke of Opole from 1396 (until 1400 with his brother as co-ruler, except Olesno).
He was the second son of Duke Bolko III of Strzelce by his wife Anna, probably daughter of Duke Jan I of Oświęcim.
Bolko II of Opole
Bolko II of Opole( before 1300 – 21 June 1356), was a Duke of Opole from 1313( with his brother as co-ruler until 1323).
He was the second son of Duke Bolko I of Opole by his wife Agnes, probably a daughter of Margrave Otto III of Brandenburg.
Bolko III of Strzelce
Bolko III of Strzelce( also known as of Opole;; – 21 October 1382) was a Duke of Opole during 1356 – 1370( with his brothers as co-rulers) and Duke of Strzelce from 1375 until his death.
He was the second son of Duke Bolko II of Opole by his wife Elisabeth, daughter of Duke Bernard of Świdnica.
Euphrosyne of Opole
Euphrosyne of Opole( and," YefrosiniyaFrosya")( 1228/30 – 4 November 1292) was a daughter of Casimir I of Opole and his wife Viola, Duchess of Opole.
She was a member of the House of Piast and became Duchess of Kujavia from her first marriage and Duchess of Pomerania from her second marriage.
Jan I of Opole
Jan I of Opole( 1410/1413 – 5 September 1439) was a Duke of Opole since 1437( with his brother as co-ruler).
He was the second son of Duke Bolko IV of Opole by his wife Margareta, possibly member of the House of Görz.
Henry of Opole
Henry of Opole( b. – d.), was a Duke of Opole from 1356 until his death.
He was the third and youngest son of Duke Bolko II of Opole and his wife Elisabeth, daughter of Duke Bernard of Świdnica.

Question: Who is the paternal grandfather of Margareta Of Opole?
Answer: Bolko III of Strzelce