Change sector or zone
Hamburg; Bremen; Lübeck… (with usage closest to Lübeck, cf.modern Lübeckisch)
mittel-niederdeutsche schriftsprache, "standard middle low german", hansesprache.
used as an administrative and also literary idiom from c.1200-1650, based on the confederation of cities in the Hanseatic League.
subsequently submerged by  Hochdeutsch-F. (High German) as official standard language in North Germany.