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.
Euphemia of Masovia
Euphemia of Masovia( 1395/97 – before 17 September 1447), was Duchess of Cieszyn by marriage to Bolesław I, Duke of Cieszyn, and regent of the Duchy of Cieszyn during the minority of her sons from 1431.
She was the third daughter of Siemowit IV, Duke of Masovia and Alexandra, daughter of Algirdas, Grand Duke of Lithuania and sister of King Władysław II Jagiełło of Poland, and thus a Polish princess member of the House of Piast in the Masovian branch.
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.
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.
Leszek of Dobrzyń
Leszek of Dobrzy ń( pl:" Leszek dobrzyński"; bef.
1302- bef. 10 July 1316), was a Polish prince member of the House of Piast and Duke of Dobrzy ń during 1312- 1316 with his brothers.
He was the eldest son of Siemowit of Dobrzy ń and Anastasia, daughter of Leo I of Halych- Peremyshl.
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.
Siemowit of Cieszyn
Siemowit of Cieszyn  (– 25 September 1391) was a Polish prince, member of the Piast dynasty in the Cieszyn branch.
He was the fifth son of Casimir I, Duke of Cieszyn, by his wife Euphemia, daughter of Duke Trojden
I of Czersk-Warsaw.
Kaya Alp
Kaya Alp was, according to Ottoman tradition, the son of Kızıl Buğa and the father of Suleyman Shah, who was, in turn, the grandfather of Ertuğrul, and the great grandfather of the Ottoman Empire founder, Osman I.
Hedwig of Cieszyn
Hedwig of Cieszyn( 1469 – 6 April 1521) was a Polish princess.
She was the only child of Przemysław II, Duke of Cieszyn by his wife Anna, daughter of Duke Bolesław IV of Warsaw.

Question: Who is Siemowit Of Cieszyn's paternal grandfather?