Duchy of Masovia was a district principality and a fiefdom of the Kingdom of Poland, existing during the Middle Ages. The state was centered in Mazovia...

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...

The Duchy of Warsaw was a feudal district duchy in Masovia, centered on the Warsaw Land. Its capital was Warsaw. The state was established in 1310, in...

death of King Casimir III the Great. Branches of the Piast dynasty continued to rule in the Duchy of Masovia (until 1526) and in the Duchies of Silesia...

Provisional Council of the Duchy of Masovia (Polish: Rada Zastępcza Tymczasowa Księstwa Mazowieckiego) was a government ad interim of Warsaw and the Masovian...

was a constituent part of some other political entities such as the Kingdom of Rus, the Kingdom of Hungary, Duchy of Masovia when eventually in the late...

Konrad I of Masovia (ca. 1187/88 – 31 August 1247), from the Polish Piast dynasty, was the sixth Duke of Masovia and Kuyavia from 1194 until his death...

Konrad I of Masovia in 1233 created the Duchy of Kuyavia for his second son Casimir I. When Casimir's elder brother Duke Bolesław I of Masovia died in...

the Duchy of Masovia, he dispatched an army to the electoral proceedings, which alienated the higher nobles and magnates. He later invaded Masovia to deprive...

the Duchy of Masovia from his nephew Leszek, becoming the progenitor of the Masovian branch of the royal Piast dynasty, and great-grandfather of the later...