Janusz III Mazowiecki or
Janusz III of Masovia (1502–1526) was a Polish
duke of MasoviaThe Dukes of Masovia were a line of the Piast dynasty who ruled in Masovia. The following is a list of all rulers of the Duchy of Masovia and its parts...
, last male of the Masovian
Piast dynastyThe Piast dynasty was the first Polish historical Royal dynasty that ruled Poland from its beginnings starting with the semi-legendary Piast Kołodziej . The first historically undisputed Piast ruler is Mieszko I from 10th century...
. Son of
Konrad III RudyKonrad III Rudy was a Polish duke of Masovia.He reunited most of Masovia still not controlled by Kingdom of Poland, including Płock, Płońsk, Czersk, Wyszogród and Warsaw....
. Until 1518 Masovia was under
regencyA regent, from the Latin regens "reigning", is a person selected to act as head of state because the ruler is a minor, not present, or debilitated. Thus, the common use is for an acting deputy governor....
of his mother Anna Radziwiłł, then he was a co-regent with his brother Stanisław until Stanisław's death in 1524. After his heirless death in 1526, the
Duchy of MasoviaThe Duchy of Masovia was a duchy formed when the Kingdom of Poland fragmented in 1138. It was reincorporated into the Polish kingdom in 1526.-History:...
was annexed into the
Kingdom of PolandThe Kingdom of Poland of the Jagiellons was the Polish state created by the accession of Jogaila , Grand Duke of Lithuania, to the Polish throne in 1386. The Union of Krewo or Krėva Act, united Poland and Lithuania under the rule of a single monarch...
.
Biography
Janusz was the younger son of
Konrad III RudyKonrad III Rudy was a Polish duke of Masovia.He reunited most of Masovia still not controlled by Kingdom of Poland, including Płock, Płońsk, Czersk, Wyszogród and Warsaw....
and Anna Radziwiłł, born in winter 1502. After his father's death in 1503 Janusz and his brother Stanisław inhertited the Czersk Land, and with support of
Alexander JagiellonAlexander Jagiellon , Grand Duke of Lithuania and later also King of Poland; he was the fourth son of Casimir IV Jagiellon...
, the throne of
Duchy of MasoviaThe Duchy of Masovia was a duchy formed when the Kingdom of Poland fragmented in 1138. It was reincorporated into the Polish kingdom in 1526.-History:...
, but due to their young age the throne was taken by their mother, Anna, who became the
regentA regent, from the Latin regens "reigning", is a person selected to act as head of state because the ruler is a minor, not present, or debilitated. Thus, the common use is for an acting deputy governor....
.
In 1518, both brothers were invited to the wedding of
Sigismund I the OldSigismund I the Old of the Jagiellon dynasty reigned as King of Poland and also as the Grand Duke of Lithuania from 1506 until 1548...
and
Bona SforzaBona Sforza d'Aragona was a member of the House of Sforza who in 1518 became the second wife of Sigismund I of Poland....
. Janusz and Stanisław fought on the Polish side during the Polish-Teutonic War (1519–1521).
Anna reigned until 1518, past the time both brothers reached the age in which they could became rulers. Eventually the disapproval of local nobility resulted in her officially transferring the power to her sons, but in fact she continued to rule the Duchy until 1522.
After their mother's death, both brothers quickly became known for their love of "women and wine". Both brothers acted as co-rulers until Stanisław's death in 1524. However Janusz ruled only until his death in the night of 9 to 10 March, 1526. He was buried in the
St. John's Cathedral, WarsawSt. John's Cathedral , located in Warsaw's Old Town, is one of 3 cathedrals in the Polish capital. St. John's stands immediately adjacent to Warsaw's Jesuit Church, and is one of the oldest churches in the city and the main church of the Warsaw archdiocese. St...
. With his death, the male line of Masovian Piasts - originating from
Siemowit III of MasoviaSiemowit III of Masovia was a prince of Masovia and a co-regent of the lands of Warsaw, Czersk, Rawa, Gostynin and other parts of Masovia. A tributary to the king of Poland Casimir III, he was from 1370 a sovereign ruler of his domain...
- died out.
The death of both brothers caused unrest, as accusations that they were murdered became widespread. Eventually king Sigismund himself looked into the matter, and concluded that there was no foulplay. A contemporary historian,
Marcin BielskiMarcin Bielski was a Polish chronicler and poet. He was born of noble parentage on the patrimonial estate of Biala , in the Polish province of Sieradz. The name Wolski is derived from his estate at Wola...
, suggested that both brothers died due to alcohol poisoning; others suggested
tuberculosisTuberculosis is a common and often deadly infectious disease caused by mycobacteria...
.
Soon after his death, the
Duchy of MasoviaThe Duchy of Masovia was a duchy formed when the Kingdom of Poland fragmented in 1138. It was reincorporated into the Polish kingdom in 1526.-History:...
was annexed into the
kingdom of PolandThe Kingdom of Poland of the Jagiellons was the Polish state created by the accession of Jogaila , Grand Duke of Lithuania, to the Polish throne in 1386. The Union of Krewo or Krėva Act, united Poland and Lithuania under the rule of a single monarch...
, 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 of MasoviaPrincess Anna of Masovia Princess Anna of Masovia Princess Anna of Masovia ( (1498 – c. 1557), last of the Masovian Piast dynasty.Anna was the daughter of Duke Konrad III Rudy and Princess Anna Radziwiłł. She married Stanisław Odrowąż in February 1536.Children: Zofia Odrowąż...
). The Polish king refused to recognize their demands, and stood by the agreements that made him the heir to the Duchy, reuniting it with Poland. The Duchy, which would became a significant asset of the Polish
Jagiellon dynastyThe Jagiellons were a royal dynasty originating from the Lithuanian House of Gediminas dynasty that reigned in Central European countries between the 14th and 16th century...
, would retain some autonomy till 1576.