Stealth originated in WW1 and by WW2 the Germans had used it on U-boats which then got the Luftwaffe thinking about either absorbing or re-directing radar which led to the Horten Ho-IX, early RAM, dielectric materials and radar-absorbing paints. The US captured the Ho-IX V3 and shipped it back home for study but stealth progress actually slowed due to lack of requirement as the SR-71 flew higher and faster than any Soviet missile cound intercept. But when the U-2 had been shot-down and Soviet missiles were gaining the advantage by the 1970s, the USAF looked for a solution. They oddly enough came upon a declassified Soviet book by Prof. Ufimtsev on radar diffraction using geometric shapes and had it translated. They then used a simple Windecker Eagle to use RAM on and then started on a military aircraft under the codename Have Blue which led to the F-117. Since it used faceting the first shape was called the "Hopeless Diamond" but they got it right after years of work by Lockheed's Skunk Works. By 1981 it was operational and in that same year when visiting MBB in W Germany they were infuriated to discover that the Germans had independently come up with a similar stealth interceptor- the MBB Lampyridae (Firefly) which was faceted as well, but more to the frontal aspect as it would be approaching Soviet bombers. Two mock-ups were made and one for RCS testing. The US Govt. and USAF put pressure on W Germany to drop the project to maintain a monopoly with stealth technology and by 1989, it was dropped; however, MBB turned into DASA and then EADS which retained the knowledge and had moved on to different designs. Some claim that a Firefly II was built as a black triangle and that two of those were CONFIRMED sighted at the Overberg Test Range in South Africa where RSA,Israel, and W Germany had agreed on shared weapons testing. The US similarly tried to pressure the UK, France, and other Euro powers, but failed as well.

http://home.xmsnet.nl/hdejong/curious/Lampyridae%20front.jpg http://discaircraft.greyfalcon.us/picturesm/gem11.jpg http://rareaircraf1.greyfalcon.us/picturesg/la1.jpg http://www.b-domke.de/AviationImages/Deutsches_Museum/Images/Lampyridae_Stealth_WTT_23494.jpg