SEELE is a German secret society of 12 (sometimes 15) creepy old men who try to bring about the End of the World by turning all of humanity into Tang. In their meetings, they present themselves holographically as huge black monoliths with numbers on them, because doing so scares the living shit out of other people at these meetings.
History of SEELE
SEELE was originally organized by Adolf Hitler to manage the Fatherland in his absence. In 1998, they successfully deciphered the clues that he'd left on the backs of the Dead Sea Scrolls regarding where he'd hidden the Spear of Longinus. They formed a bunch of not-so-secret organizations like GEHIRN and NERV and tried to kill everybody in 2015. They successfully implimented humanity after an attack on NERV, and as a result, Tang, as mentioned above.
Fuck it, it's 2 AM where I live, I gotta stop writing this shit and get some fucking sleep. You guys finish this. It's 4:30 for me...