Temple knights

Temple Knights maybe greater in number than the Whhite Knights of Falador and beyond. You have a chance to join the Temple Knights during a Recruitment drive. To become a White Knight after that you need to either need to spend five years as a squire or do something great like the Wanted quest.

Temple Knights are strong in strength and number because they are the ones who sent the doomed expedition to the God Wars Dungeon.

Also during the Wanted quest you are given a communication orb that tells you they moniter the teleportation matrix and makes it seem like you might be dealing with a large and secretive organization. The Temple Knights also summoned a group of level 99 rangers to aid you out of nowhere which proves their strength is greater than most wish to reveal.

To me, the Temple Knights sort of resemble CIA...