Crescent Winged Aircraft
 

When was the first time the crescent wing was conceptualized and when was the first aircraft to actually use a crescent wing?

The first I can think of was the David R. Davis' Manta

Arado patent in 43. HP nicked it in 45.

And first employed on the Victor, although HP made a couple of proof of concept development aircraft called the HP80 using Supermarine Attacker fuselages. A clever design which demonstrated how advanced the Germans really were in WW2. Although building it was very expensive and the interior structure made it heavy.

HP80 was the designation for what eventually became the Victor. The test aircraft based on the Supermarine Attacker was the HP88. It didn't survive long, breaking up in mid air while preparing for the 1951 Farnborough air show, and apparently didn't really contribute to the development programme as by that time the full size prototypes were well under way. The second research aircraft was the HP87, a half size glider.
http://olimpmodels.com/olimp.files/HP88.jpg

Oops - got my 80s and 88s mixed up. Should have known that, especially as I used to fly the 80!

@msbbarratt

Varying the sweep and fineness ratio to keep a constant Mcrit while shedding vortices at the kinks to keep low drag and giving good low speed handling according to my old notes.