Theodred II (Bishop of Elmham)
Theodred II was a medieval Bishop of Elmham.
The date of Theodred's consecration unknown, but the date of his death was sometime between 995 and 997.
Wenceslaus of Płock
Wenceslaus (Wańko) of Płock (Masovian dialect: "Wańko Puocky"; 1293/97 – 23 May 1336), was a Polish prince member of the House of Piast, Duke of Płock since 1313 and vassal of Bohemia from 1329.
He was the third son of Bolesław II of Płock but the only born from his second marriage with Kunigunde, daughter of King Ottakar II of Bohemia.
He was probably named after his maternal uncle, King Wenceslaus II of Bohemia.
Leszek, Duke of Masovia
Leszek of Masovia( also" Lestek")( b. ca. 1162- d. 1186) was a Polish prince from the Piast dynasty, the Duke of Masovia from 1173 until his death.
He was the only son of Bolesław IV the Curly, Duke of Masovia and High Prince of Polan, who survived father.
After his father death he inherited Masovia.
At the beginning, Leszek ruled under the guardianship of his uncle Casimir II the Just.
He was a man of poor health.
For a short time he supported his other uncle, Mieszko III the Old, but later decided to reconciled with Kazimierz II, who after Leszek's death inherited his duchy.
Odolan
Odolan( d. 1145) was a Polish nobleman.
During the reign of Bolesław III Krzywousty
He was probably" comes" of Poznań or Gniezno.
After his death supported his younger sons against his oldest son Władysław II Wygnaniec.
Odolan was probably" wojewoda" of younger sons of Bolesław III.
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.
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.
Bolesław I of Masovia
Bolesław I of Masovia( 1208 – ca. 25 February 1248), was Polish prince member of the Polish House of Piast, Duke of Sandomierz( only a part) during 1229- 1232, Duke of Dobrzy ń during 1233- 1247 and Duke over whole Masovia during 1247- 1248.
He was the second son of Konrad I of Masovia and Agafia of Rus.
He was probably named after his great- grandfather, Bolesław III Wrymouth.
The death of his older brother Przemysł in 1228 left him as the eldest surviving child of his family.
Bolesław III of Płock
Bolesław III of Płock (pl: "Bolesław III płocki"; 1322/30 – 20 August 1351), was a Polish prince member of the House of Piast, Duke of Płock since 1336 (under regency until 1340), ruler over Wizna and Sochaczew since 1345, formally a vassal of the Kingdom of Bohemia during all his reign.
He was the only son of Wenceslaus of Płock and Dannila (Elisabeth), a daughter of Gediminas, Grand Duke of Lithuania.
Margaret of Masovia
Margaret of Masovia( before 1358 – 14 May 1388/4 April 1396) was Duchess of Pomerania and Brzeg, by her marriages to Casimir IV, Duke of Pomerania and then to Henryk VIII with a Scar.
She was a member of the House of Piast.
Margaret was a daughter of Siemowit III of Masovia and his wife Euphemia of Opawa.
Her paternal grandparents were Trojden I of Masovia and his wife Maria, daughter of Yuri I of Galicia and Euphemia of Kuyavia.

Question: When did Bolesław Iii Of Płock's father die?
Answer: 23 May 1336