History of Poland during the Piast dynasty in the context of "Mongol invasion of Kievan Rus'"

Sorbs (Upper Sorbian: Serbja; Lower Sorbian: Serby; German: Sorben pronounced [ˈzɔʁbn̩] ; Czech: Lužičtí Srbové; Polish: Serbołużyczanie; also known as Lusatians, Lusatian Serbs and Wends) are an indigenous West Slavic ethnic group predominantly inhabiting the parts of Lusatia located in the German states of Saxony and Brandenburg. Sorbs traditionally speak the Sorbian languages (also known as "Wendish" and "Lusatian"), which are closely related to Czech and Lechitic languages. Upper Sorbian and Lower Sorbian are officially recognized minority languages in Germany.

In the Early Middle Ages, the Sorbs formed their own principality, which later shortly became part of the early West Slavic Samo's Empire and Great Moravia, as were ultimately conquered by the East Francia (Sorbian March) and Holy Roman Empire (Saxon Eastern March, Margravate of Meissen, March of Lusatia). From the High Middle Ages, they were ruled at various times by the closely related Poles and Czechs, as well as the more distant Germans and Hungarians. Due to a gradual and increasing assimilation between the 17 and 20 centuries, virtually all Sorbs also spoke German by the early 20 century. In the newly created German nation state of the late 19 and early 20 centuries, policies were implemented in an effort to Germanize the Sorbs. These policies reached their climax under the Nazi regime, who denied the existence of the Sorbs as a distinct Slavic people by referring to them as "Sorbian-speaking Germans". The community is divided religiously between Roman Catholicism (the majority) and Lutheranism. The former Minister President of Saxony Stanislaw Tillich is of Sorbian origin.

From the 1220s to the 1240s, the Mongols conquered the Turkic states of Volga Bulgaria, Cumania and Iranian state of Alania, and various principalities in Eastern Europe. Following this, they began their invasion into Central Europe by launching a two-pronged invasion of then-fragmented Poland, culminating in the Battle of Legnica (9 April 1241), and the Kingdom of Hungary, culminating in the Battle of Mohi (11 April 1241). Invasions were also launched into the Caucasus against the Kingdom of Georgia, the Chechens, the Ingush, and Circassia though they failed to fully subjugate the latter. More invasions were launched in Southeast Europe against Bulgaria, Croatia, and the Latin Empire. The operations were planned by General Subutai (1175–1248) and commanded by Batu Khan (c. 1207–1255) and Kadan (d. c. 1261), two grandsons of Genghis Khan. Their conquests integrated much of Eastern European territory into the empire of the Golden Horde. Warring European princes realized they had to cooperate in the face of a Mongol invasion, so local wars and conflicts were suspended in parts of central Europe, only to be resumed after the Mongols had withdrawn. After the initial invasions, subsequent raids and punitive expeditions continued into the late 13th century.

Melik, one of the princes from the Ögedei family who participated in the expedition, invaded the Transylvania region of the Hungarian kingdom, called Sasutsi in sources.

Lower Silesia (Polish: Dolny Śląsk [ˈdɔlnɨ ˈɕlɔ̃sk]; Czech: Dolní Slezsko; German: Niederschlesien [ˈniːdɐˌʃleːzi̯ən] ; Silesian: Dolny Ślōnsk; Upper Sorbian: Delnja Šleska [ˈdɛlnʲa ˈʃlɛska]; Lower Sorbian: Dolna Šlazyńska [ˈdɔlna ˈʃlazɨnʲska]; Lower Silesian: Niederschläsing; Latin: Silesia Inferior) is a historical and geographical region mostly located in Poland with small portions in the Czech Republic and Germany. It is the western part of the region of Silesia. Its largest city is Wrocław.

The first state to have a stable hold over the territory of what will be considered Lower Silesia was the short-lived Great Moravia in the 9th century. Afterwards, 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. The oldest Polish writing and first Polish print were created in the region. During the Ostsiedlung, the Piast rulers invited German settlers to settle in the region, which until then had a Polish majority. As a result, the region became largely German-speaking by the end of the 15th century.

The Eastern Neisse, also known by its Polish name of Nysa Kłodzka (German: Glatzer Neiße, Czech: Kladská Nisa), is a river in southwestern Poland, a left tributary of the Oder, with a length of 188 km (21st longest) and a basin area of 4,570 km (3,742 in Poland).

Prior to World War II it was part of Germany. During the Yalta Conference it was discussed by the Western Allies as one possible line of the western Polish border. Attempts were made to negotiate a compromise with the Soviets on the new Polish-German frontier; it was suggested that the Eastern Neisse be made the line of demarcation. This would have meant that (East) Germany could have retained approximately half of Silesia, including most of Wrocław (formerly Breslau). However the Soviets rejected the suggestion at the Potsdam Conference and insisted that the southern boundary between Germany and Poland be drawn further west, at the Lusatian Neisse, in some way reintroducing the border to the place from the beginnings of Polish statehood, i.e. west of Legnica Town, important for Bolesław IV the Curly and Henry the Bearded, two Polish Princepses.

The Duchy of Teschen (German: Herzogtum Teschen), also Duchy of Cieszyn (Polish: Księstwo Cieszyńskie) or Duchy of Těšín (Czech: Těšínské knížectví), was one of the Duchies of Silesia centered on Cieszyn (Teschen) in Upper Silesia. It was split off the Silesian Duchy of Opole and Racibórz in 1281 during the feudal division of Poland and was ruled by Silesian dukes of the Piast dynasty from 1290 until the line became extinct with the death of Duchess Elizabeth Lucretia in 1653.

The ducal lands initially comprised former Lesser Polish territories east of the Biała River, which in about 1315 again split off as the Polish Duchy of Oświęcim, while the remaining duchy became a fiefdom of the Bohemian kings in 1327 and was incorporated into the Lands of the Bohemian Crown in 1348. While the bulk of Silesia was conquered by the Prussian king Frederick the Great in the Silesian Wars of 1740–1763, Teschen together with the duchies of Troppau (Opava), Krnov and Nysa remained with the Habsburg monarchy and merged into the Austrian Silesia crown land in 1849. The so-called "commander line" of the Habsburg-Lorraine dynasty, a cadet branch descending from Archduke Charles, Duke of Teschen, held the title "Duke of Teschen" until 1918.

The Kraków Voivodeship (Polish: Województwo Krakowskie, Latin: Palatinatus Cracoviensis) was a voivodeship (province) in the Kingdom of Poland from the 14th century to the partition of Poland in 1795 (see History of Poland during the Piast dynasty, Kingdom of Poland (1385–1569), and Polish–Lithuanian Commonwealth). Located in the southwestern corner of the country, it was part of the Lesser Poland region (together with two other voivodeships of Poland: Sandomierz Voivodeship, and Lublin Voivodeship) and the Lesser Poland Province.

A konfederacja (Polish: [kɔ̃fɛdɛˈrat͡sja] , confederation, confederacy) was an ad hoc association formed by the nobility (szlachta), clergy, and municipalities to pursue their stated aims or act in place of state authority, created in Poland and Lithuania between the 13th and 19th centuries. A konfederacja often took the form of an armed union aimed at redressing perceived abuses or trespasses by some authority, such as the royal authority. These "confederations" acted in place of state authority or to force their demands upon that authority.

They could be seen as a primary expression of direct democracy and the right of revolution in the Polish–Lithuanian Commonwealth, allowing nobles to act on their grievances and against the central authority. Its origins can be traced back to medieval resistance law (Latin: ius resistendi) against the ruler. A characteristic feature of the confederation was named membership: the list of its members was drawn up at the time of its formation. Since the formation occurred for the realisation of a predetermined goal, the confederation was temporary.