Polish mining immigration to Belgium between 1918 and 1939 is a significant, yet overlooked phenomenon. Despite difficult circumstances, Polish miners did not constitute a socially radical group. In fact, we witness quite opposite attitudes: focusing on honest work, religion and family. To understand this situation, we need to reconstruct various factors that influenced Polish miners in Belgium. An analysis led to dividing these factors into two categories: destabilising and stabilising.The former are rapid migration dynamics, blocked social advancement and communist activity. The latter I found in the presence of old mining societies and — most importantly — Polish diaspora’s concentration, which slowed down the assimilation and also dispersion processes. Overall, Belgium was not treated as a necessary evil and after many years the province of Limburg was still called the “Belgian Silesia”. ; Polish mining immigration to Belgium between 1918 and 1939 is a significant, yet overlooked phenomenon. Despite difficult circumstances, Polish miners did not constitute a socially radical group. In fact, we witness quite opposite attitudes: focusing on honest work, religion and family. To understand this situation, we need to reconstruct various factors that influenced Polish miners in Belgium. An analysis led to dividing these factors into two categories: destabilising and stabilising.The former are rapid migration dynamics, blocked social advancement and communist activity. The latter I found in the presence of old mining societies and — most importantly — Polish diaspora’s concentration, which slowed down the assimilation and also dispersion processes. Overall, Belgium was not treated as a necessary evil and after many years the province of Limburg was still called the “Belgian Silesia”. ; Polish mining immigration to Belgium between 1918 and 1939 is a significant, yet overlooked phenomenon. Despite difficult circumstances, Polish miners did not constitute a socially radical group. In fact, we witness quite opposite ...