The Germania Slavica was introduced by Wolfgang H. Fritze as a research term in the mediaeval terminology when his interdisciplinary working group (IAG) was founded in 1976. This term was first used by Walter Schlesinger in 1961, as an analogy to 1932 research term Germania Romana coined by Theodor Frings . The Germania Romana designated, according to Frings, the spaces "in which German language development [...] has been determined by the influence of Roman substrates ", essentially the areas west of the Rhine and Neckar and south of the Altmühl and the Danube ( Limes ).