This chapter addresses the history of the German settlements worldwide, starting with the population movements in the Middle Ages and the emergence of the so-called Sprachinseln in Eastern Europe and Upper Italy. It then describes the second wave of emigration starting in the seventeenth century to Eastern Europe and Russia. This movement is characterized as a population movement that was planned and guided from above. After that the parallel emigration overseas, to the Americas, Australia and South Africa, is illustrated in more detail and similarities and differences are discussed. This section also illustrates the extraordinary position of Namibia where German had been a co-official language over decades. In all cases the post-war development, which in most cases led to the dissolution of the German language communities, is specifically focused on. In a second part of this chapter the phenomenon of border minorities which emerged after World War I is addressed. Finally, the individual migration of German speakers between the wars and in the post-war period will be illustrated.

The chapter looks at the effect of natural barriers on linguistic configuration and diffusion through illustrations of cases from Arabic and other languages. It provides examples of how different types of topographical features either facilitate or hinder communication, thus affecting the diffusion of linguistic features. It also provides a thorough introduction to the Arabic linguistic atlases available, from 1915 into the twenty-first century. The chapter highlights cases of language isolation and language contact involving Arabic.