After the First Lantern is subdued for going crazy, a sect of Guardians decide to keep watch over him while the rest of the Guardians fix the universe.
Rise of the Third Army
When the old Guardians decided that the time of the Green Lantern Corps was up, they visit the Chamber of Shadows to retrieve the First Lantern. They are met by the Templar Guardians who ask if the Universe is safe once more. The old Guardians brush off the Templars and proceed to the First Lantern's prison. A skirmish ensues between the two factions of Guardians and ends only when one of the Templars are killed.
The old Guardians leave with the First Lantern and imprison the Templars.
Wrath of the First Lantern
The Templar Guardians are freed from the Chamber of Shadows during the fight between Simon Baz and Black Hand. But Simon is sucked into Black Hand's ring leaving the Templars and B'dg to deal with Black Hand. The two work together to pull out Simon from the Black Ring and mange to do so with the addition of Sinestro. The Templars try to enlist Sinestro's help but he disappears.
The Templars travel to Maltus in search of the Great Heart with hopes of saving the old Guardians but First Lantern beats them to it.
After killing his share of the Guardians of the Universe, Sinestro deems the Templar Guardians to be the Guardian's collective second chance.
Years after it was revealed that the Templar Guardians have come to serve the Corps well and true. Unlike the old Guardians they exhibit emotions and are more revered by the Corps than before.