Havířov was founded after World War II (thus being the youngest city in today's Czech Republic) as a coal mining town. Havířov officially became a town in 1955. It was built on top of several villages with significant Polish populations. The local people were given apartments in the newly built city, and most of their old houses were demolished to make room for new urban buildings. The majority of the population of Havířov immigrated from other parts of Czechoslovakia, many of them from Slovakia, as migrant workers, thus substantially altering the ethnic structure of the area. Today, the original villages are administratively part of the city and mostly lie on the outskirts of urban Havířov.