Henry III, Duke of Głogów
Henry III and the Bohemian King Ottokar II formed a coalition of Silesian Princes to help the prisoner Duke.
One year later Henry III participated in the great Battle on the Marchfeld (26 August 1278), where King Ottokar II was defeated and killed.
In the same year Henry III was forced to make a division of his lands between his brothers: he retained the main cities of the Duchy —Głogów, Bytom Odrzański and Kożuchów—; Konrad II the Hunchback obtained Ścinawa and Przemko received Żagań and Nowogród Bobrzański; soon after Konrad II went to study in Bologna, and Henry IV Probus took his lands in his name; with this, the ruler of Wroclaw showed his intentions to stretch his sovereignty over all the other Głogów princes and Silesian rulers.
However, one year later, on 23 June 1290, Henry IV Probus died suddenly, probably poisoned,[6] an event which seriously affected the further career of the Duke of Glogów.
Henry III made a treaty with the House of Wettin, strengthening this alliance by marrying the daughter of Duke Albert I of Brunswick-Lüneburg, Matilda (March 1291).
With the latter Henry III entered into an arrangement under which if Przemysł II died without male issue, the Duke of Głogów would inherit his lands.
Henry III and Władysław I quickly concluded a settlement on 10 March 1296 in Krzywin, under which the Duke of Głogów obtained all the lands from the south of the Obra River.
The reason Henry III gave large concessions to Władysław I in the treaty of 1296 was that he was already defeated by Bolko I the Strict, Duke of Jawor.
In June 1298, in Kościan (and despite the opposition of the Greater Poland nobility with the Bishop of Poznan Andrzej Zaremba at their head) Henry III and Władysław I signed a new treaty, under which in return for confirmation of the church and the inclusion in a future "Kingdom" of the functions of Chancellor, Henry III promised assistance to Władysław I in order to complete the total subjection of Greater Poland, Gdańsk Pomerania and in this way he could obtain the Royal crown.
In the village of Klęka on 23 August 1299 an agreement was concluded under which Henry III was forced to abandon his pretentions over all Greater Poland for good.
Henry III accepted immediately the intervention of the Bohemian King, because he was busy in his own duchy with his disputes with the Bishop of Wroclaw Jan Romka.
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.
In the internal politics, Henry III could maintain his Duchy far away from the wars where he was constantly involved, and in consequence, the economy improved and with this the prestige and wealth of Głogów increased.
His five sons: Henry IV, Konrad I, Jan, Boleslaw and Przemko II, soon split between them the inheritance of his father and led to the decline of the Duchy.
Moreover, this political fragmentation, visible especially in the Greater Poland region, scared the local nobility, who thought that maybe they risked losing their positions.
