Abstract
Demographic trends in the Czech lands in the twentieth century were influenced by the socio-political developments. Both world wars and their consequences played a significant role.
The number of people living on the territory of the contemporary Czech Republic grew from 9,3 million in 1910 to 10,5 million in 2015 and at the same time the proportion of Czechs grew from approximately 66 % in 1900 to 94 % in 2001. The structure of the population also changed considerably.