Duke of Masovia
The Dukes of Masovia were the sons and descendants of the Polish Duke Bolesław III Wrymouth. In accordance with the last will and testament of Bolesław, upon his death his lands were divided into 4-5 hereditary provinces distributed among his sons, and a royal province of Kraków reserved for the eldest, who was to be High Duke of all Poland. This was known as the fragmentation of Poland. Subsequent developments lead to further splintering of the duchies.
The following is a list of all rulers of the Duchy of Masovia and its parts. Although not all incumbents listed here had titular rights to the title of Duke of Masovia, they are all listed as such for simplicity's sake.
Also take note that some of the dates are merely approximate and the ownership of certain lands might be disputed. Finally, this table does not include lands ruled by dukes of other parts of partitioned Poland or Wenceslaus II and Wenceslaus III.
Duchy of Masovia
Partitions of Masovia
The Duchy went through various border changes in the coming years, sometimes losing and sometimes gaining territory.
Duchy of Masovia
| Duchy of Masovia |
In 1233, the Duchy of Kujavia of emerged from Masovia.
Duchy of Kujavia
| Duchy of Masovia | Duchy of Kujavia | |||
In 1313, Masovia is divided in the Duchies of Płock, Czersk and Rawa.
Duchy of Czersk Duchy of Rawa Duchy of Płock
| Duchy of Kujavia | Duchy of Rawa | Duchy of Czersk | Duchy of Płock | |||
In 1327, Kujavia is annexed by Poland
| Duchy of Rawa | Duchy of Czersk | Duchy of Płock |
In 1349, Warsaw emerged form Czersk
Duchy of Warsaw
| Duchy of Rawa | Duchy of Czersk | Duchy of Warsaw | Duchy of Płock |
In 1434, Belz emerged form Płock,tobe annexed again in 1442
Duchy of Belz
| Duchy of Rawa | Duchy of Czersk | Duchy of Warsaw | Duchy of Płock | Duchy of Belz |
| Duchy of Rawa | Duchy of Czersk | Duchy of Warsaw | Duchy of Płock |
In 1462, Rawa is annexed to Poland. The same happens with Płock in 1495.
| Duchy of Czersk | Duchy of Warsaw |
Konrad III reunites Czersk and Warsaw, to recreate the Duchy of Masovia, annexed by Poland in1526.
Dukes of Masovia
Piast Dynasty
| Ruler | Reign | Ruling Part | Notes | |
|---|---|---|---|---|
| Bolesław the Curly |  | 1138-1173 | Masovia | Son of Bolesław III Wrymouth of Poland. Also Duke of Silesia and monarch of Poland. |
| Leszek I | 1173-1186 | Masovia | Son of Bolesław the Curly. | |
| Casimir the Just |  | 1186-1194 | Masovia | Son of Bolesław III Wrymouth of Poland. Also monarch of Poland. |
| Leszek II the White |  | 1194-1200 | Masovia | Son of Casimir the Just. Ruled jointly with his brother Conrad I. Also monarch of Poland. |
| Conrad I |  | 1194-1247 | Masovia | Son of Casimir the Just. Ruled jointly with his brother Leszek II until 1200. Also monarch of Poland. |
| Casimir I |  | 1233-1267 | Kujavia | Son of Conrad I. His father granted him with the Duchy of Kujavia in 1233. After his death, the duchy is divided in Inowrocław and Brześć Kujawski. As Brześć Kujawski was already annexed by the Teutonic Order since 1228, only the duchy of Inowrocław will be mentioned here. |
| Bolesław I |  | 1247-1248 | Masovia | Son of Conrad I. |
| Siemowit I |  | 1248-1262 | Masovia | Brother of Bolesław I. |
| Conrad II |  | 1262-1294 | Masovia | |
| Siemomysł | 1267-1271 | Kujavia-Inowrocław | Son of Casimir I. 1st time. | |
| Bolesław the Pious |  | 1271-1278 | Kujavia-Inowrocław | Ruled jointly with Leszek the Black since 1273. |
| Leszek I the Black |  | 1273-1278 | Kujavia-Inowrocław | Ruled jointly with Boleslaus the Pious. |
| Siemomysł | 1278-1287 | Kujavia-Inowrocław | Son of Casimir I. 2nd time. | |
| Leszek II |  | 1287-1314 | Kujavia-Inowrocław | Son of Siemomysl. Ruled jointly with his brothers Przemysł and Casimir II. 1st time |
| Przemysł |  | 1287-1314 | Kujavia-Inowrocław | Son of Siemomysl. Ruled jointly with his brothers Leszek II and Casimir II. 1st time |
| Casimir II |  | 1287-1314 | Kujavia-Inowrocław | Son of Siemomysl. Ruled jointly with his brothers Przemysł and Leszek II. |
| Bolesław II |  | 1294-1313 | Masovia | Divided the Duchy among his sons. |
| Trojden I |  | 1313-1341 | Czersk | First ruler of Czersk. Son of Boleslaus II. |
| Leszek II | | 1314-1324 | Kujavia-Inowrocław | Ruled alone. 2nd time |
| Siemowit II |  | 1313-1345 | Rawa | First ruler of Rawa. Son of Boleslaus II. |
| Wenceslaus I |  | 1313-1336 | Płock | First ruler of Płock. Son of Boleslaus II. |
| Przemysł | | 1324-1327 | Kujavia-Inowrocław | Ruled alone. 2nd time. In 1327, Kuyavia is annexed by the Kingdom of Poland. |
| Bolesław III | 1336-1351 | Płock | Son of Wenceslaus. In 1351 Płock was annexed by the Kingdom of Poland. | |
| Casimir I | 1341-1349 | Czersk | Son of Trojden I. Also duke of Warsaw and Rawa. | |
| Casimir I | 1345-1349 | Rawa | Also duke of Czersk and Warsaw. | |
| Casimir I | 1349-1355 | Warsaw | First duke of Warsaw. | |
| Siemowit III |  | 1349-1370 | Czersk | Brother of Casimir I. Also duke in Rawa and Warsaw. |
| Siemowit III | | 1355-1370 | Rawa | Also Duke in Czersk and Warsaw. |
| Siemowit III | | 1349-1370 | Warsaw | Also duke in Rawa and Czersk. |
| Siemowit III | | 1370-1381 | Masovia | Brought Płock from Poland in 1370, reuniting the duchy of Masovia, but after his death it was divided between his sons Janusz I and Siemowit IV. |
| Janusz I |  | 1381-1429 | Warsaw | son of Siemowit III, since 1386 hereditary vassal of Poland, after 1391 Duke of Podlasie. Although the division, the duchy of Czersk remained annexed to the duchy of Warsaw. |
| Siemowit IV |  | 1381-1426 | Płock | Son of Siemowit III. Although the division, the duchy of Rawa remained annexed to the duchy of Płock. Since 1386, hereditary vassal of Poland, and, although having lost much of his domain to the Teutonic Order in 1382 (Wizna, Zawkrze, Płońsk), he gained other duchies (Bełz) from Poland. |
| Trojden II | 1426-1427 | Płock | Son of Siemowit IV. Ruled jointy with his brothers Casimir II, Władysław I, and Siemowit V. | |
| Władysław I |  | 1426-1455 | Płock | Son of Siemowit IV. Ruled jointy with his brothers Casimir II, Trojden II, and Siemowit V until 1434 |
| Casimir II | 1426-1434 | Płock | Son of Siemowit IV. Ruled jointy with his brothers Trojden II, Władysław I, and Siemowit V. | |
| Siemowit V | 1426-1434 | Płock | Son of Siemowit IV. Ruled jointy with his brothers Casimir II, Władysław I, and Trojden II. Also duke of Rawa. | |
| Bolesław IV |  | 1429-1454 | Warsaw | Until 1436 regency of his mother, Anna Feodorovna, between 1440 and 1444 only as Duke of Podlasie |
| Casimir II | 1434-1442 | Bełz | In 1434 Bełz emerged from Płock, to be annexed again in 1442. | |
| Siemowit V | 1434-1442 | Rawa | In his reign Rawa had a briefperiod of independence, but after his death, Rawa rejoined Płock. | |
| Bolesław V |  | 1454-1488 | Warsaw | Son of Bolesław IV. Ruled jointly with his brothers Conrad III, Casimir III and Janusz II, until 1471. In this year, Boleslaus V loses Czersk for his brother Conrad the Red. |
| Conrad III the Red |  | 1462-1471 | Warsaw | Son of Boleslaus IV. Ruled jointly with his brothers Conrad III, Casimir III and Janusz II. |
| Casimir III | 1462-1471 | Warsaw | Son of Boleslaus IV. Ruled jointly with his brothers Conrad III, Casimir III and Janusz II. | |
| Janusz II |  | 1462-1471 | Warsaw | Son of Boleslaus IV. Ruled jointly with his brothers Conrad III, Casimir III and Janusz II. |
| Siemowit VI | 1455-1462 | Płock | Son of Władysław I. Ruled jointy with his brother Władysław II. | |
| Władysław II | 1455-1462 | Płock | Son of Władysław I. Ruled jointy with his brother Siemowit VI. | |
| Conrad III the Red | | 1462-1471 | Płock | |
| Casimir III | 1471-1475 | Płock | ||
| Janusz II | | 1475-1495 | Płock | In 1495 Płock is annexed by the Kingdom of Poland. |
| Conrad III the Red | | 1471/1488/1495-1503 | Masovia | Reunited the duchies which remained independent (Czersk and Warsaw, gained between 1471 and 1488) to recreate the Duchy of Masovia, in 1495. |
| Stanisław I |  | 1503-1526 | Masovia | Ruled jointly with his brother Janusz III. |
| Janusz III |  | 1503-1526 | Masovia | Ruled jointly with his brother Stanisław I. |
| Anna |  | 1526 | Masovia | The last Masovian Piast. Sister of Stanislaus and Janusz III. Anna was elected duchess by the nobles to maintain the independence of the Duchy. It was unsuccessful, because, in the same year, Masovia was annexed to the Kingdom of Poland. |
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