|This article does not cite any references or sources. (December 2009)|
According to Pomponius Mela (3.31, 3.54) and Pliny the Elder (4.96), it is an "enormous bay" lying beyond the Elbe". It has "many small islands", the largest one being Scandinavia (the manuscripts of Mela have Codannovia).
The origin of the name is obscure.