シロンスク公国
Initially part of the Piast Duchy of Silesia, the Oleśnica area became part of the Duchy of Głogów in 1294, following an armed conflict between Duke Henry III of Głogów and his cousin Henry V the Fat, Duke of Wrocław. After the death of Duke Henry III in 1309, it gained significant autonomy during the division of the Głogów lands and the creation of the Duchy of Oleśnica for Henry's son Bolesław in 1313, succeeded by his brother Konrad I in 1321.