The Force War

The Force War was the last major battle between the Orders of the Jedi and the Sith. This war lasted decades, spanning most of the known Galaxy, claiming trillions of lives and scarring an untold number of worlds. This war came about in an effort by the Sith to force the galaxy under it's control and wipe out the Jedi Order once and for all. At the end, when the battle turned against the Sith, they attempted one last act of spite to collapse the entire galaxy into the super massive black hole at the center of the galaxy.

Aftermath
The War left the galaxy scarred and devastated. The loss of life was never totalled, but was estimated to be in the hundreds of trillions. Public Opinion turned against any use of the Force and any Force Using Tradition, even the Jedi.

As a result, many Force Purges and Hunts were held to wipe out any trace of the Force that could be found. Force Sensitive Crystal Caves were destroyed, races with the ability to use the Force were heavily culled, ruins and temples of old Force Traditions were razed. The Republic and Empire could not stop this tide of public wrath against the Force, and were helpless to stop these acts of hatred.

In the end, the survivng members of the Jedi Order decided to go into self imposed Exile and removed themselves from the Galaxy, knowing that the time of the Jedi was over, and that they were no longer needed or welcomed by the people they had fought so hard to save.