Kazimierz III of Gniewkowo

Kazimierz III of Gniewkowo (Polish: Kazimierz III gniewkowski; ca. 1280/84 – 22 August 1345/13 May 1350), was a Polish prince member of the House of Piast, Duke of Inowrocław during 1287-1314 (under the regency of his mother until 1294 and his brother during 1294-1296), since 1306 vassal of the Kingdom of Poland, Governor of the Duchy of Pomerelia (Gdańsk Pomerania) during 1306-1309 (on behalf of his uncle Władysław I the Elbow-high), since 1314 ruler over Gniewkowo (between 1332-1343 deposed by the Teutonic Order).

He was the third and youngest son of Ziemomysł of Inowrocław and Salomea, daughter of Sambor II, Duke of Pomerelia.

After the death of their father in 1287, Kazimierz III and his older brothers Leszek and Przemysł inherited his domains; however, because they are minors, remained under the regency of their mother and paternal half-uncle Władysław I the Elbow-high until 1294, when Leszek, as the oldest brother, attained his majority and assumed the government and the guardianship of his brothers. Kazimierz III attained his majority ca. 1302, but initially ruled jointly with his brothers; two years previously (in 1300) he was forced to paid homage to King Wenceslaus II of Bohemia.

In 1306 he paid homage to his uncle Władysław I, in return for which he was appointed Governor of Gdańsk Pomerania, with his base in Tczew. In 1309, he was forced to abandon his post as a result of the invasion of the Teutonic Order, despite a personal conversation with the Komtur Heinrich von Plötzke, even asked him on his knees to return the cities taken by the Teutonic Knights to his rightfil owner, Władysław I, but without success.

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