Stanisław of Masovia
Stanisław of Masovia (pl: "Stanisław mazowiecki"; 17 May 1501 – 8 August 1524), was a Polish prince member of the House of Piast in the Masovian branch.
He was a Duke of Czersk, Warsaw, Liw, Zakroczym and Nur during 1503-1524 (under regency until 1518) jointly with his brother.
He was the eldest son of Konrad III the Red and his third wife Anna, a daughter of Mikolaj Radziwiłł "the Old", Voivod of Vilnius and the first Grand Chancellor of Lithuania.
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 Dobrzy ń) 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.
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.
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.
Lyon Cohen
Lyon Cohen( 1868–1937) was a Polish- born Canadian businessman and a philanthropist.
He was the grandfather of singer/ poet Leonard Cohen.
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.
Abd al-Muttalib
Abd al- Muttalib Shaybah ibn Hashim( c. 497 – 578) was the grandfather of Islamic prophet Muhammad.
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.
Gaudemunda of Lithuania
Gaudemunda Sophia of Lithuania( also Gaudimantė; c. 1260 – 1288/1313) was the daughter of Traidenis, Grand Duke of Lithuania( c. 1270 – 1282).
In 1279 she married Duke of Masovia Bolesław II( c. 1254–1313) of the Piast dynasty.
He was the son of Ziemowit I, Prince of Masovia, and Pereyaslava, daughter of Daniel of Galicia of the Rurik dynasty.
Her husband united the Duchy of Masovia and then divided it between their sons, who were:
Konrad III Rudy
Konrad III the Red
(pl: "
Konrad III Rudy"; 1447/48 – 28 October 1503), was a Polish prince member of the House of Piast in the Masovian branch.
He was a duke of Czersk, Liw, Warsaw, Nur, Łomża, Ciechanów, Różan, Zakroczym and Wyszogród during 1454-1471 jointly with his brothers (under regency until 1462), Duke of Płock, Wizna, Płońsk and Zawkrze during 1462-1471, and after the division of the paternal domains in 1471, sole ruler over Czersk and Liw, over Wyszogród during 1474-1489 and again in 1495, over Zakroczym since 1484, over Nur since 1488 and over Warsaw since 1489.
He was the third son of Bolesław IV of Warsaw and Barbara Olelkovna of Slutsk-Kapy, a Lithuanian princess, (granddaughter of Vladimir Olgerdovich).
The premature death of his two older brothers during 1453-1454 left him as the eldest surviving son of his family.

Question: Who is Stanisław Of Masovia's paternal grandfather?
Answer: Bolesław IV of Warsaw