Flag of Czech Silesia, historical region

Czech Silesia (Czech: České Slezsko; Polish: Śląsk Czeski) is the part of the historical region of Silesia now in the Czech Republic. Czech Silesia is, together with Bohemia and Moravia, one of the three historical Czech lands. Historical population Year Pop. ±% 1869 419,707 — 1880 464,646 +10.4% 1890 501,635 +8.0% 1900 572,000 +14.0% 1910 638,404 +11.6% 1921 654,433 +2.5% 1930 716,698 +9.5% 1950 604,498 −15.7% 1961 737,872 +22.1% 1970 842,454 +14.2% 1980 894,725 +6.2% 1991 895,776 +0.1% 2001 887,141 −1.0% 2011 846,855 −4.5% 2021 811,433 −4.2% Source: Censuses Silesia lies in the north-east of the Czech Republic, predominantly in the Moravian-Silesian Region, with a section in the northern Olomouc Region. It is almost identical in extent with Austrian Silesia (also known as the Duchy of Upper and Lower Silesia), before 1918; between 1938 and 1945, part of the area was also known as Sudeten Silesia (German: Sudetenschlesien; Czech: Sudetské Slezsko; Polish: Śląsk Sudecki).