Lower Silesia (Polish: Dolny Śląsk; Czech: Dolní Slezsko; German: Niederschlesien; Upper Sorbian: Delnja Šleska; Lower Sorbian: Dolna Šlazyńska; Latin: Silesia Inferior; Silesian German: Niederschläsing; Silesian: Dolny Ślůnsk) is the northwestern part of the historical and geographical region of Silesia; Upper Silesia is to the southeast.
In the Middle Ages Lower Silesia was part of Piast-ruled Poland. It was one of the leading regions of Poland, and its capital Wrocław was one of the main cities of the Polish Kingdom. Lower Silesia emerged as a distinctive region during the fragmentation of Poland, in 1172, when the Duchies of Opole and Racibórz, considered Upper Silesia since, were formed of the eastern part of the Duchy of Silesia, and the remaining, western part was since considered Lower Silesia. During the Ostsiedlung, German settlers were invited to settle in the sparsely populated region, which until then had a Polish majority. As a result, the region became largely Germanised in the following centuries.
In the late Middle Ages the region fell under the overlordship of the Bohemian Crown, however large parts remained under the rule of local Polish dukes of the Piast dynasty, some up to the 16th and 17th century. Briefly, under the suzerainty of the Kingdom of Hungary, it fell to the Austrian Habsburg Monarchy in 1526.
In 1742, Austria ceded nearly all of Lower Silesia to the Kingdom of Prussia in the Treaty of Berlin, except for the southern part of the Duchy of Nysa. Within the Prussian kingdom, the region became part of the Province of Silesia. In 1871, Lower Silesia was integrated into the German Empire. After World War I, the region became a separate province within the Weimar Republic.
After 1945, the main part of the former Prussian province fell to the Republic of Poland, while a smaller part west of the Oder-Neisse line remained within East Germany and historical parts of Austrian Lower Silesia (Jesenicko, Opavsko regions) remained as a part of Czechoslovakia. By 1949, almost the entire pre-war German population was expelled.The region is known for an abundance of historic architecture of various styles, including many castles and palaces, well preserved or reconstructed old towns, numerous spa towns, and historic burial sites of Polish monarchs and consorts (in Wrocław, Legnica and Trzebnica).