Upon the death of his cousin Duke Casimir I of Opole, son of Mieszko I Tanglefoot, in 1230, he acted as guardian of his minor nephews, thereby once again ruling over whole Silesia.
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The residence of Wrocław fell to his younger brothers Henry III the White and Władysław, thereby establishing the Duchy of Wrocław proper.
Silesia | Grand Duchy of Lithuania | Duchy of Brabant | Duchy of Saxony | Duchy of Carinthia | Duchy of Burgundy | Upper Silesia | Duchy of Cornwall | Lower Silesia | Grand Duchy of Hesse | Grand Duchy of Mecklenburg-Schwerin | Province of Silesia | Duchy of Parma | Chancellor of the Duchy of Lancaster | Duchy of Warsaw | Duchy of Prussia | Duchy of Jülich | Lorraine (duchy) | Grand Duchy of Baden | Duchy of Milan | Duchy of Mecklenburg-Schwerin | Duchy of Lancaster | Duchy of Holstein | Duchy of Savoy | Duchy of Nassau | Duchy of Limburg | Duchy of Württemberg | Duchy of Pomerania | Duchy of Luxembourg | Grand Duchy of Oldenburg |
Henry had acquired the strip of former Lubusz Land up to Fürstenberg (today's Eisenhüttenstadt) from the Silesian duke Bolesław II Rogatka in turn for his mediation in the duke's conflict with his Piast brother Henry III the White.