Such a delimitation and division of the Low German area does, however, have its problems: for example, in the west it is arguable that Saxon dialects extend over the Dutch-German frontier towards the Zuider Zee. Conversely, it is questionable if the Low Franconian dialects north of the Benrath line and east of the political border should be considered Low German. One possible solution would be to ascribe the various dialects to the respective standard language (Uberdachungssprache) in each area. Such theoretical considerations may, however, soon prove unnecessary as recent research would seem to indicate that the political border is now increasingly becoming a linguistic border. The 'Benrath Line', the miikenmachen isogloss running from west to east is also problematic. It is generally considered to be the boundary between High and Low German as for a large distance it is joined by other isoglosses marking the limits of the High German or second sound shift. It might, though, be better to regard the division between High and Low German not as a sharp boundary but rather as a transitional zone varying in width. (For further details and some of the problems connected with this boundary see Chapter 3.)
2 The Functions of Low German Today the term Low German refers to the Low German dialects alone, as there is no supradialectal norm. The use of the dialects varies from region to region but is generally restricted to a number of communicative functions all involving a degree of personal contact. This has not always been the case, as Middle Low German was in the heyday of the Hanseatic League, from about the thirteenth to the sixteenth century, an international language of trade and commerce in the whole of the area around the North Sea and the Baltic. Middle Low German was also an important written language, as witnessed by sundry documents which have been preserved down to the present day. The demise of Middle Low German set in with the decline of the Hansa and the introduction of High German into the formal public sphere, marking the beginning of a language contact situation in which the two languages have existed side by side down to the present day. A gradual change took place in the linguistic situation in north Germany and by the middle of the seventeenth century Low German had been replaced by High German as the official written language. Since then there has been a steady reduction of its functions so that today it is practically only found as a spoken language in the family and local area, and to a certain degree at work.