

In 1870, the population in the Austria-Hungarian Empire consisted of:
? The census held
in 1921 in Czechoslovakia revealed that the Czechs
held a very narrow majority in this multi-ethnic country:
Czechs
6.7 million
Sudeten Germans
3.1 million
Slovaks
2.0 million
Hungarians
0.7 million
Ruthenians
0.5 million
Jews
0.3 million
Poles
0.1 million.
There was a "revolutionary" Czechoslovak National Assembly of which not a single German, Hungarian, Ruthenian or Pole was a member, and in which only some hand-picked Slovaks were included. This Assembly enacted the Czechoslovak Constitution on February 19, 1920. The Constitution was never approved or ratified by a referendum or a parliament elected by all citizens. In the Constitution reference was made to a "Czechoslovak nation" which in fact did not exist: the other ethnic groups living the CSR were not even mentioned.
NOTE:
Between 1945-1950
a total of 2,921,000 German refugees and expellees
Came from Czechoslovakia.
A total of 250,000 ethnic Germans remained there after 1950.
Dead or missing
in flight and expulsion: 267,000.