Jugend ("Youth" in German) was a German art magazine that was created in the late 19th century. It featured many famous Art Nouveau artists and is the source of the term "Jugendstil" ("Jugend-style"), the German version of Art Nouveau. The magazine was founded by writer Georg Hirth. It was published from 1896 to 1940. (Wikipedia Entry)
From Tony Langley's collection of period illustrations.