Jedi

Jedi represent the good side of the Force in the Star Wars continuum.

They are dedicated to helping others and are the opposing number to the Sith.

Making a Jedi engage in a relationship before the creation of the New Jedi Order by Luke Skywalker is a charge, unless your story is set before the Great Sith War.

Origins
According to Wookiepedia, the Jedi began as a Gathering of the Galaxy's best Philosophers, Priests, Scientists, and Warriors on the planet Tython.

First Great Schism
The first split between darksiders and orthodox Jedi, This conflict is often confused with the Force Wars, even on Wookiepedia.

Second Great Schism/Hundred-Year-Darkness
The Hundred-Year-Darkness was the event that ultimately sparked the exile of the darksiders who eventually formed the Sith Empire.

Great Hyperspace War
The Sith Empire is rediscovered by two hyperspace explorers, and attacks the Galactic Republic.

The reign of Freedon Nadd
Six centuries later, a renegade Jedi Knight by the name of Freedon Nadd felt the lure of the dark side and was taught by Naga Sadow's spirit on Yavin IV. After learning all that it knew, He then "extinguished" it and went to the planet Onderon, where he became king of the local inhabitants and spread darkness throughout the world.

Great Sith War
It was only after this conflict that Jedi were forbidden to have relationships.

Jedi Civil War
The first KOTOR game is set in this era.

Links
http://starwars.wikia.com/wiki/History_of_the_Jedi_Order