The Nordic Indo-Germanic people is a mythological group, from which the Germanic peoples allegedly descended. The assumption of the existence of this primordial people was developed by nationalists in the German territories from the early 19th century onwards, and was the subject of intense research in both the 19th and 20th centuries. Nineteenth-century German philologists, ethnologists and historians initially focused their research on the Eastern origins of Germanic populations. Then, in a second phase, these researchers (or their followers) changed the focus of their work to demonstrate the Nordic origin of Germanic populations and civilization. These results were soon deliberately exploited in the debate on German identity that raged throughout the nineteenth century.
From the 1920s onwards, the results of research and speculation on this hypothetical people were used by the extremist pangermanists known as the Nazis to claim immense territories for the German nation, the nucleus of a future Greater German Reich. These territories, which the Third Reich claims to have been occupied in the past by Indo-Germanic populations, are intended to constitute the "living space" of the Greater Germanic people, gathered around its German core, and to support the policy of maintaining the Aryan "race purity", through a systematic hunt for those possessing the "lost Germanic genes" so dear to Himmler.