- 1921
- 13,410,750
- 1938
- 14,800,000
- Capital and largest city
- Prague
- Official languages
- Czechoslovak
- Common languages
- List Czechoslovak ( Czech · Slovak ), German , Hungarian , Rusyn , Romani , Polish , Yiddish
- Demonym
- Czechoslovak
- Government
- Unitary parliamentary republic
- 1918 1935
- Tomáš Masaryk
- 1935 1938
- Edvard Beneš
- 1918 1919 first
- Karel Kramář
- 1938 last
- Jan Syrový
- Legislature
- National Assembly
- Upper house