Janusz I of Warsaw
Janusz I. starszy ( Janusz I. " the Elder ", * ca 1346, † December 8, 1429 in Czersk ) was from 1373/1374 Duke of Mazovia in Warsaw, from 1381 through inheritance also of Mr. Only, Łomża, Liw, Ciechanów, Wyszogród, Zakroczym and Podlaskie.
When Duke of Mazovia he was a vassal of the Polish Crown and came from the Mazovia line of the Piast dynasty.
Janusz I. was the eldest son of the Duke Siemowit III. of Mazovia. His brother was Siemowit IV
Polish policy
In its policy Janusz I held on to the close cooperation with Poland and its next rulers of Louis I of Anjou, Hedwig of Anjou and Władysław II Jagiello. In this way, Janusz I. protested against the policy of his brother Siemowit IV, with whom he wanted to gain the Polish crown for himself. After the death of Casimir " the Great ", he handed the Polish crown directly to Ludwig I, King of Hungary and Croatia, and nephew of the last Piast from the line of Kujawy Piast dynasty on the Polish throne.
Janusz I. and the German Order
The friendly relations between Poland and Lithuania after decision by the Union caused the permanent state of hostility on the side of the Teutonic Order. In 1393 there was, for unknown reasons, on the kidnapping of the Prince in connection with the construction of his castle on the border of Mazovia, near the river Narew by the Commander Rudolf on behalf of the Grand Master Konrad von Jungingen. The King Władysław II Jagiello intervened and the German Order set him free again. In 1404, the Teutonic Knights Duke Janusz I, together with his wife and their sons kidnapped again. Here, too, caused King Władysław II Jagiello second intervention for the release of the Duke of Mazovia. In 1409, Commander and Commander Ostróda Brandenburg drove to the Principality 's Janusz I.
Family
Janusz I. starszy was married to the daughter of the Lithuanian Grand Duke Vytautas Kiejstut and sister - Danuta Anna, with whom he continued three sons into the world: Janusz Młodszy, Bolesław Januszowic and Konrad Januszowic.
Janusz I. starszy died on 8 December 1429 Czersk and was buried in the St. John's Cathedral (Warsaw).