Calopteryx virgo (Linnaeus, 1758) – Beautiful Demoiselle
NL: Bosbeekjuffer | DE: Blauflügel-Prachtlibelle | FR: Caloptéryx vierge

Calopteryx virgo (Beautiful Demoiselle) imagos are mostly found near moderately to fast flowing streams, containing submerged vegetation and usually in or near forests. Male imagos aggressively defend territories nearby suitable larval habitat, perching in plants and trees overlooking the stream between fights.
Distribution of Beautiful Demoiselle covers pretty much all of Europe, parts of North Africa and stretches eastward all the way to Japan.