Anna of Racibórz
Anna of Racibórz( b. 1292/98 – d. 1 January/ 21 August 1340), was a Polish princess member of the House of Piast in the Racibórz branch and by marriage Duchess of Opawa and Racibórz.
She was the second child but eldest daughter of Duke Przemysław of Racibórz by his wife Anna, daughter of Duke Konrad II of Masovia.
Anna of Masovia, Duchess of Racibórz
Anna of Masovia( c. 1270- after July 13, 1324) was a Princess of Masovia and was a member of the House of Piast.
She was the daughter and only child of Konrad II of Masovia and Hedwig, daughter of Bolesław II the Bald.
Between 1289 and 1290 Anna married Przemysław of Racibórz.
Anna was Duchess of Racibórz along with her unnamed sister- in- law.
She was then widowed May 7, 1306.
With her husband, Anna had the following children:
Is also believed that Constance, who ruled in Wodzisław Śląski until her death in 1351 was also her daughter.
When her son Leszek was old enough to exercise power over the principality, Anna probably moved to Wodzislaw where she lived with the consent of her son.
She lived with her supposed third daughter Constance.
After her death, Anna was buried in Raciborz, presumably the Dominican Church or the Dominican monastery.
Kunigunde of Bohemia
Kunigunde of Bohemia( January 1265 – 27 November 1321) was the eldest daughter of Ottokar II of Bohemia and his second wife, Kunigunda of Slavonia.
She was a member of the Přemyslid dynasty.
She was Princess of Masovia by her marriage to Boleslaus II of Masovia and later became abbess of the St. George's Convent at Prague Castle.
Sophia of Masovia
Sophia of Masovia( 1497/1498- before 11 March 1543) was a Princess of Masovia, daughter of Konrad III Rudy, Duke of Masovia and his wife Anna Radziwiłł.
She was a member of the House of Piast.
On 17 September 1520 in Warsaw, Sophia was married by proxy to Stephen VII Báthory.
On 17 January 1521, Sophia and her entourage went to Hungary, where in February there was a formal marriage.
The couple had three children:
Anna, Stephen and Klara; however, other sources claim that Klara was the couple's only child.
Klara was engaged to Carl, Duke of Münsterberg, but died in 1535, before the marriage took place.
After the death of Stephen in 1530, Sophia was married to Croatian magnate Louis Pekry.
Sophia's second marriage was childless.
She then died sometime before 11 March 1543.
Sophia had three siblings: Stanislaus I of Masovia, Janusz III of Masovia and Anna of Masovia, both her brothers died childless and so Anna and Sophia were the last Masovian Piasts.
Soon after Janusz's death, the Duchy of Masovia was annexed into the kingdom of Poland, despite resistance from some of the Masovian nobility.
They tried to retain their independence and argued that the Duchy should be inherited by the female relatives( such as Anna or Sophia).
The Polish king refused to recognize their demands.
Anna was made titular Duchess of Masovia.
Siemowit III, Duke of Masovia
Siemowit III of Masovia( his name also rendered Ziemowit; – 1381) was a prince of Masovia and a co-regent( with his brother Casimir I of Warsaw) of the lands of Warsaw, Czersk, Rawa, Gostynin and other parts of Masovia.
Konrad II of Masovia
Konrad II of Czersk (pl: "Konrad II czerski"; c. 1250 – 24 June/21 October 1294), was a Polish prince member of the House of Piast, Duke of Masovia during 1264-1275 jointly with his brother, since 1275 sole ruler over Czersk and Duke of Sandomierz during 1289.
He was the eldest son of Siemowit I of Masovia and Pereyaslava, a daughter of Prince Daniel of Halych.
Euphemia of Racibórz
Euphemia of Racibórz( 1299/1301 – 17 January 1359) was a Polish princess member of the House of Piast in the Racibórz branch and Dominican Prioress in Racibórz.
She was the third child but second daughter of Duke Przemysław of Racibórz by his wife Anna, daughter of Konrad II of Masovia.
Leszek of Racibórz
Leszek of Racibórz( 1292 – 1336) was a Duke of Racibórz since 1306 and Duke of Koźle from 1334 until his death.
He was the eldest child and only son of Duke Przemysław of Racibórz by his wife Anna, daughter of Duke Konrad II of Masovia.
Siemowit I of Masovia
Siemowit I of Masovia  (c. 1224/28 – 23 June 1262), was a Polish prince member of the House of Piast, Duke of Czersk during 1247-1248, Duke of Masovia (except Dobrzyń) during 1248-1262, ruler over Sieradz during 1259-1260.
He was the sixth son of Konrad I of Masovia and his wife Agafia of Rus.
He was named after his older brother Siemowit, who died young in 1224.
Anna of Masovia
Anna of Masovia( c. 1498 – after 26 January 1557 in Jaroslaw) was Princess of Mazovia and a member of the House of Piast.
She was the last representative of the line of Masovian- Piast.
She was the second daughter of Konrad III of Masovia and Anna Radziwiłł.
She was a sister of Dukes Janusz III of Masovia and Stanislaus of Masovia, and Sophia, who married Stephen VII Báthory.

Question: Who is Konrad Ii Of Masovia's paternal grandfather?
Answer: Konrad I of Masovia