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In page Henry III, Duke of Głogów:

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In the spring of 1306 Henry III was able to advance over the Greater Poland-Kuyavia borderline (Konin) and Gdańsk Pomerania, forcing Władysław I the Elbow-high to retreat. Kalisz resisted the pretentions of the Duke of Głogów, but he was able to master it in 1307 from his current ruler, Duke Bolesław III the Generous (the eldest son of Henry V the Fat), who also had a claim over the whole succession of Wenceslaus (as the husband of her youngest daughter Margareta); eventually, all Greater Poland was taken by the Duke of Głogów. Soon Henry III and the new King of Bohemia Henry of Carinthia formed an alliance against Bolesław III's ambitious plans.