The book (originally entitled Vom "Westfälischen Slowenen" zum "Gastarbeiter", first published in 2016) deals with Slovenian labour migration to Germany in the 19th and 20th centuries. The first groups of miners and farmers settled in the Ruhr area around 1872 and became known as the “Westphalian Slovenes".” A larger wave of immigration took place after 1968, when Slovenes were employed en masse in the Bavarian automotive industry, particularly at Audi in Ingolstadt, following the Yugoslav-German agreement on the recruitment of foreign labour. Based on archive sources and many years of research, the book analyses the migration routes, living conditions, cultural life, the role of social institutions and trade union organisation. It shows the change from coal mining to the metal industry, but also broader social changes such as gender relations and generational differences among migrants. A central focus is the comparison between the “Westphalian” and the “Bavarian” Slovenian migrant communities of the post-war period.