Duke of Masovia () was a title borne by 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 four to five 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.
Dukes of Masovia and Kuyavia
Piast dynasty
Partitions of Masovia and Kuyavia under Piast dynasty
The Duchy went through various border changes in the coming years, sometimes losing and sometimes gaining territory.
+ Duchy of Masovia(1st creation)(1138-1275) Duchy ofŁęczyca(1267-1351) Duchy ofDobrzyńDobrzyń was left to Poland, in exchange with Leczyca, which survived as independent a few more years.(1267-1327)Duchy ofKuyaviaThe duke of Kuyavia became, 1320, King of Poland, which motivated more exchanges and interventions of the Polish kingdom in the Kuyavian land.(1247-1333)Duchy ofCzersk(1st creation)(1275-1294) Duchy of Płock(1st creation)(1275-1294) Duchy ofGniewkow(1287-1364) Duchy ofInowrocław(1267-1333) Duchy ofWarsaw(1st creation)(1313-1495)Duchy ofRawa(1st creation)(1313-1355) Annexedto Poland Annexedto Poland Annexedto Poland(1355-1370) Annexedto Poland Duchy ofRawa(2nd creation)(1426-1459)Rawa was annexed to Płock in 1442, but Gostynin, part of Rawa, survived as independent until 1459.Duchy ofPłock(2nd creation)(1381-1462) Duchy ofCzersk(2nd creation)(1471-1495) Duchy ofPłock(3rd creation)(1471-1495)Duchy of Masovia(Czersk line; 2nd creation)(1495-1526)
Table of rulers