The Human Instrumentality Project

The Human Instrumentality Project, sometimes referred to as Human Complementation Project as well, is the backbone of the storyline. Everything somehow is related to this project.
Driving force behind the Human Instrumentality Project is a secret organisation called SEELE, it's foundation and whereabout's are unknown.
The beginning was made with the Dead Sea Scrolls, found in Qumran. In this scrolls, the coming of angels and their destruction, followed by mankinds salvation was prophesied.
In 1999, Project E was founded. Ikari Yui joined the project soon, later her friend, Rokubungi Gendo, Fuyutsuki Kohzoh and Akagi Naoko were introduced the group now called GEHIRN.
GEHIRN's goal was the creation of a perfect being.
In 2000, the Katsuragi-expedition to Antarctica went underway, and they found Adam. Unfortunately, the capturing of Adam wasn't too successful, the giant of light caused a huge explosion, later known as Second Impact. One third of earth's population died in that event, Katsuragi Misato was the only survivor of this expedition...and Ikari Gendo, who seemed to know enough to leave early.
But with Adam's DNA, birth was given to Evangelion Unit-00, the prototype of a god under the command of man.