Following the revolt against the thinking machines, humans were forced to develop their minds to take the place of outlawed computers, and established mental training schools. Meant for females, the Bene Gesserit school was one of the most prominent training facilities established.
Bene Gesserit sisters managed to work their ways in to the inner circles of nearly every important leader in the Imperium.
For 90 generations the Bene Gesserit engaged in a breeding program to bring about the superbeing Kwisatz Haderach. Because the Bene Gesserit conceived a son with Duke Leto Atreides, the Kwisatz Haderach was born before the Bene Gesserit expected in the form of Paul Atreides. Paul was able to successfully take the water of life, awakening his full powers.