Duchy of Silesia - Geography

Geography

During the time of its establishment, the Silesian lands covered the basin of the upper and middle Oder river. In the south the Sudetes mountain range up to the Moravian Gate formed the border with the lands of Bohemia - including Kłodzko Land - and Moravia. After a more than century-long struggle, the boundary had just been determined by a 1137 agreement with the Bohemian duke Soběslav I. In the west Lower Silesia bordered on the German March of Lusatia (later Lower Lusatia) and the former Milceni lands around Bautzen (later Upper Lusatia) with the boundary running along the Bóbr and Kwisa rivers. Silesia was limited by the Polish provinces of Greater Poland in the north and the Seniorate Province of Lesser Poland in the east, separated by the Przemsza and Biała rivers.

The boundaries varied slightly in the following decades: at least when the duchy was re-established for the sons of Władysław II the Exile in 1163 (see below), it also comprised Lubusz Land northwest of Krosno, which formerly was the western outpost of Greater Poland and passed to the margraves of Brandenburg in 1248. In 1177 the Polish High Duke Casimir II the Just attached the former Lesser Polish castellanies of Bytom, Oświęcim, Zator, Siewierz und Pszczyna to Upper Silesia in favour of Duke Mieszko IV Tanglefoot. After Silesia as a whole had become a Bohemian fief according to the 1335 Treaty of Trentschin, these lordships - except for the state countries of Bytom and Pszczyna - returned to the Polish Crown.