Duchy of Rawa

The state was established in April 1313, in the partition of the Duchy of Płock, with duke Siemowit II of Masovia becoming its first leader. It existed until 5 November 1370, when, under the rule of duke Siemowit III, duchies of Czersk, Rawa, and Warsaw were unified into the Duchy of Masovia. It was again reestablished in June 1381, in the partition of the Duchy of Masovia, with duke Siemowit IV as its first leader. It existed until 1488, when it got incorporated into the Duchy of Czersk.

From 1310 to 1320, it was a fiefdom within the Kingdom of Poland, and from 1320 to 1385, a fiefdom of the United Kingdom of Poland, and from 1386 to 1442, a fiefdom of the Crown of the Kingdom of Poland.

List of rulers

First state

• Siemowit II of Masovia (1313-1345)
• Siemowit III and Casimir I of Warsaw (1341–1349)
• Siemowit III (1349–1370)

Second state

• Siemowit IV (1381–1426)
• Trojden II of Płock, Casimir II of Belz, Władysław I of Płock, and Siemowit V of Masovia (1426–1427)
• Casimir II of Belz, Władysław I of Płock, and Siemowit V of Masovia (1427–1434)
• Siemowit V of Masovia (1434–1442)