Frederick William, Duke of Cieszyn
Frederick William of Cieszyn (9 November 1601 – 19 August 1625) was a Duke of Cieszyn since 1617 until his death.
He was the third but only surviving son of Adam Wenceslaus, Duke of Cieszyn, by his wife Elisabeth, daughter of Gotthard Kettler, Duke of Courland.
His mother died from childbirth complications ten days after his birth, on 19 November 1602.
Ludwik III of Oława
Louis III of Oława, mostly known as of Lüben( before 1405 – before 18 June 1441), was a Duke of Oława( Ohlau) from 1419/20 and Duke of Lubin( Lüben) and Chojnów( Haynau) from 1431 until his death.
He was the third and youngest son of Henry IX, Duke of Lubin, by his wife Anna, daughter of Przemyslaus I Noszak, Duke of Cieszyn.
Casimir I, Duke of Cieszyn
Casimir I of Cieszyn (1280/90 –), was Duke of Cieszyn from 1315, Duke of Siewierz from 1337 and Duke of Bytom from 1357.
He was the second son of Mieszko I, Duke of Cieszyn by his wife, probably called Grzymisława.
Wenceslaus II, Duke of Cieszyn
Wenceslaus II of Cieszyn( b. 1488/96- d. 17 November 1524), was a Duke of Cieszyn since 1518 until his death( as co-ruler of his father).
He was the second son of Casimir II, Duke of Cieszyn, by his wife Johanna, daughter of Wiktoryn of Poděbrady, Duke of Opawa.
Przemyslaus I Noszak, Duke of Cieszyn
Przemysław I Noszak (1332/1336 – 23 May 1410), was a Duke of Cieszyn-Bytom-Siewierz from 1358 (during 1359–1368 he lost Siewierz and in 1405 also lost Bytom), from 1384 ruler over half of both Głogów and Ścinawa (except during 1404–1406) and since 1401 ruler over Toszek.
He was the third son of Casimir I, Duke of Cieszyn, by his wife Euphemia, daughter of Duke Trojden
I of Czersk-Warsaw.
Rupert II of Lubin
Rupert II of Lüben( 1396/1402 – 24 August 1431) was a Duke of Lubin( Lüben) and Chojnów( Haynau) since 1419/ 20 until his death.
He was the eldest son of Henry IX, Duke of Lubin, by his wife Anna, daughter of Przemyslaus I Noszak, Duke of Cieszyn.
Elizabeth Lucretia, Duchess of Cieszyn
Elizabeth Lucretia of Cieszyn; 1 June 1599 – 19 May 1653), was a reigning Duchess of Cieszyn( Teschen, Těšín) from 1625 until her death.
Born as the third child and second daughter of Adam Wenceslaus, Duke of Cieszyn( by his wife Elisabeth, daughter of Gotthard Kettler, Duke of Courland), she was the last ruler of Cieszyn from the Polish Piast dynasty.
Wenceslaus III of Oława
Wenceslaus III of Oława( 1400 – between 14 January and 28 May 1423), was a Duke of Oława( Ohlau) since 1419/ 20 until his death.
He was the second son of Henry IX, Duke of Lubin, by his wife Anna, daughter of Przemyslaus I Noszak, Duke of Cieszyn.
Bolesław I, Duke of Cieszyn
Bolesław I of Cieszyn( – 6 May 1431) was a Duke of half of Bytom and Siewierz from 1405, Duke of Cieszyn and half of both Głogów and Ścinawa from 1410, and Duke of Toszek and Strzelin during 1410 – 1414.
He was the second son of Przemysław I Noszak, Duke of Cieszyn by his wife Elisabeth, daughter of Bolesław, Duke of Koźle- Bytom.
In the chronicle of Jan Długosz he is named the eldest son, but this is certainly a mistake, because elsewhere, Przemysław of Oświęcim was always placed before Bolesław.
Wenceslaus III Adam, Duke of Cieszyn
Wenceslaus III Adam of Cieszyn (December 1524 – 4 November 1579) was a Duke of Cieszyn from 1528 until his death.
He was the second but only surviving son of Wenceslaus II, co-Duke of Cieszyn, by his wife Anna, daughter of Frederick I, Margrave of Brandenburg-Ansbach.
He was born one month after his father's death, on 17 November 1524.

Question: Who is Przemyslaus I Noszak, Duke Of Cieszyn's paternal grandfather?
Answer: Mieszko I, Duke of Cieszyn