This fly is NOT called Europe!
The name of this renown fly is Europea 12 - with an a - oftentimes just called E-12. It's a true European classic, a great caddis imitation and even easy to tie.
The origin of this fly is French. So far so good. But from there it becomes increasingly difficult to establish its history. Some say that it was tied by Tony Burnand as a part of a series, others refer to André Ragot as the one who designed the series - which by the way contains 12 flies according to some sources, and up to 37 according to others!
Burnand was a friend of Charles Ritz, and the editor of the French fishing magazine Au Bord de l'Eau. André Ragot was also a well known person in French fishing, and since they were active during the same pre-WW II period they can't even be separated by time.
I have tried to track down more details of the origins of the Europea flies, but have failed in doing so. For now it must suffice to say that the Europea 12 is French.
Our first meeting
My own intro to this fly did not come from Fance, but from Sweden in the form of Swedish Lennart Bergqvist's excellent book "Flugbinding på mitt sätt" (Fly-tying My Way), which was one of the first fly-tying books I bought, and which covers a lot of trout flies for stream fishing, including a bunch of caddis flies and amongst them a number of Europea 12 variations.
It's not a surprise that Bergkvist covers this fly, because it's a very popular fly in Sweden, and is often referred to simply as E-12, E:12 or E-12:an as the Swedes put it (pronounced e-tolvan).
The classic and the variations
There's a lot of variations around. That's how it is with simple and classic patterns like this. People seem to be unable to leave them simple, and have to add and improve.
A common variation includes CDC under the wing, which is a slight variation, but other styles of the pattern differ so much from the original that it hardly makes sense to call it a Europea 12 fly any more.
My personal version is relatively loyal to the original, although I omit the tail just as Bergquist does. Caddises do after all have no tail. The wing on the fly was originally tied using mallard hen chest feathers, but you can basically use any feather with the right shape - even pheasant or chicken hackle. Personally I often tie the fly with just one feather for the wing, although the original seems to prescribe two. Since the feather is tied centrally on the top of the hook shank, I see no reason to use two feathers unless you want volume or stiffness.
I like to keep the fly low profile with a slender body and a wing that lies flat over the body, straddling it slightly. Some people tie the wing longer than I do - up to 1½ times the hook length. I personally prefer the wing to end over the hook bend. And I like an even, well defined and rather bushy hackle that gives the fly some frontal volume and support. Other E:12's are tied with sparse hackles, but I like the volume and I think the profile of the somewhat beefy and clumsy natural caddises calls for a sturdy front to the fly. I have seen E-12's tied with maybe 5-6 turns of hackle and even some using the technique where two hackles are mixed - like a brown and a grizzly. I usually use one hackle and find 3-4 turns enough to create the volume I want. But even a beefy E:12 will not be a fly with a lot of volume. Tied as described above the fly is actually quite slender and low profile.
I also like dark colors for the materials - brownish rather than tan - which also contrasts the yellow tying thread in a way that appeals to me more than maybe the fish.
Fishing the E.12
Fishing the fly is no big deal. It's fished like any caddis: drifted still in the surface with the experimental streak or twitch to see if that can attract attention. It's not a super floater and treating it with some floatant can aide its time in the surface. But should it get drenched and start sinking beyond what amadou or some dry shake can cure, do not necessarily change to a new fly, but try fishing it just in the surface.
The fly can have a tendency to land on its side or even upside down, which shouldn't worry you too much. The fish don't seem to mind, so neither should you. If you are bothered by your E:12 flies not landing upright, you can consider trimming the underside of the hackle, which can sometimes force the fly to sit nicely in the surface with the wing and body over and in the film and the hook point under.