The population of Germany manifests trends characteristic of most advanced industrial countries: lower marriage rates, delayed marriage and child-bearing, low fertility rates, small household size, high divorce rates, and extended life expectancy. The population of indigenous Germans has been in decline since 1972 in the west and since 1969 in the east because the number of births has not kept pace with the number of deaths. In 1990 only five of the sixteen Länder registered growth in population because of natural increase.

Since the 1950s, the population of Germany has become more various. Millions of foreigners have migrated to Germany, seeking employment, citizenship, or asylum. In contrast to the native population, foreigners in Germany tend to have more children and larger households. In 1988 their average household size was 3.5 persons. Depending upon their origins and social status, foreigners in Germany have been integrated into society in widely varying degrees.

Characteristic of Germany, throughout its history, has been the deficiency of clearly defined geographic boundaries, particularly on the great lowland of northern Europe; both the area occupied by the German peoples and the boundaries of the German state (at such times as it existed) have fluctuated constantly. The German people appear to have originated on the coastal region of the Baltic Sea and in the Baltic islands in the Bronze and early Iron ages. From about 500 BC they began to move southward, crushing and absorbing the existing Celtic kingdoms; from 58 BC onward they clashed along the line of the Rhine and Danube rivers with the power of Rome. With the fall of the Roman Empire, German peoples, predominantly under Frankish tribal leadership, closely settled a large area west of the Rhine River in what is still German territory; they also penetrated deeply into Belgium and areas that later became France. The Merovingian and Carolingian empires knew no distinction between what are now France and western Germany; it is understandable that Charlemagne is recognized as an valuable figure in the history of both countries.