query: conflict 23rd infantry division 
supports: The 23rd Upper Silesian Infantry Division ( Polish : 23 . Gornoslaska Dywizja Piechoty ) was a unit of the Polish Army in the interwar period ( 1921 - 1939 ) . Created in 1921 , its headquarters were stationed in Upper Silesian town of Tarnowskie Góry . Also , some other units were located in garrisons across the Polish part of Upper Silesia : in Katowice - 73rd Infantry Regiment , in Tarnowskie Gory - 11th Infantry Regiment , in Chorzów , Rybnik and Wielkie Hajduki - 75th Infantry Regiment , in ory and Bdzin - 23rd Light Artillery Regiment . In October 1938 the Division , under General Jan Jagmin - Sadowski , participated in the annexation of Zaolzie . A year later , in September 1939 , it took part in the Polish September Campaign . Commanded by Colonel Wladyslaw Powierza , it was part of Operational Group `` Silesia '' / `` Jagmin '' of the Army Kraków , under General Antoni Szylling . On September 1 and 2 , the unit defended the so - called Fortified Area of Silesia , then it was ordered to support the 55th I.D. , which was fighting around Wyry and Kobiór . After several skirmishes with German 28th I.D. , the Poles withdrew towards the Nida River . Between September 4 and 20 , the Division retreated eastwards , repelling German attacks and beating the enemy in Bigoraj . On September 19 , the Division joined units attacking Tomaszów Lubelski , but these efforts were fruitless . It fought until the capitulation of Army Kraków , September 20 . Upper Silesia (Silesian: "Grny lnsk" ; Silesian German: "Oberschläsing") is the southeastern part of the historical and geographical region of Silesia. Since the 9th century, Upper Silesia has been part of (chronologically) Greater Moravia, the Duchy of Bohemia, the Piast Kingdom of Poland, again of the Lands of the Bohemian Crown and the Holy Roman Empire, as well as of the Habsburg Monarchy from 1526. In 1742 the bulk of Upper Silesia was annexed by the Kingdom of Prussia, and in 1871 it became part of the German Empire. After the Second World War it became part of the Republic of Poland, in 1945. Silesian German (Silesian German: ' or ') or Lower Silesian is a nearly extinct German dialect spoken in Silesia. It is part of the East Central German language area with some West Slavic influences. Variations of the dialect until 1945 were spoken by about seven million people. After World War II, local communist authorities forbade the use of the language, after the expulsion of the Germans the province of Silesia was incorporated into southwestern Poland, with small portions in northeastern Czech Republic and in eastern Germany, and Silesian German continued to be spoken only by individual families expelled to the remaining territory of Germany and in cultural gatherings mainly in West Germany. Most descendents of the Silesian Germans expelled to West and East Germany no longer learned the dialect, and the cultural gatherings were less and less frequented.
candidates: world war world war ii
answer: world war ii