The Order was founded thousands of years ago in Egypt. Its goal is to protect defenceless humans from the vicious creatures that lurk in the shadows, awaiting an opportunity to strike. One of its first missions was helping King Kreon of Thebes defeat a zombie army led by Antigone and her brother Polyneikes (which is the subject of the yet unpublished prequel Antigone: Zombie Revenge). The Order has faced many threats, which is why it takes the training of its recruits very seriously. They must not only excel at physical tasks, but also master the use of specially designed weapons, as well as study its vast collection of texts on supernatural creatures. Even more important, they must be willing to give their lives if needed be to fulfill their duty.
Much of its methods look somewhat outdated, but they're quite effective. In Lesson One: Vampires, Tim uses a variety of medieval weapons and in Mummy Issues, a katana, but never a gun. Also in Mummy Issues, Ben attacks him with a fiery alchemical preparation. Monster slayers are also good at improvising, as Tim showed in Tim's Winter Adventure when he turned a half-chewed candy cane into a lethal weapon. The Order also encourages its slayers to adopt a more antiquated manner of speaking because it's been shown to increase civilians' trust in their abilities and made them more willing to follow directions.
The Order's current secret headquarters are in Romania, on the tallest and most inaccessible of the Carpathian mountains. It's always led by a trio of veteran monster slayers as surviving into old age in such a dangerous occupation makes them natural role models for their successors. The bravest and most dedicated monster slayers get a portrait in the hero gallery. However, the Order's triumphs can make its slayers a target for revenge. In Lesson One: Vampires, Countess Báthory (more about the historical figures we made vampires here) tells Tim she's been killing monster slayers as payback for the Order killing her vampire husband, and plans to do the same to him. She also reveals that more than one slayer has been turned into one of the very monsters they're trained to hunt.
In the end of Lesson One it's revealed that the Elders had allied themselves with the German National Socialist Party and started targeting non-humans simply for not being humans rather than being threats as a way to cleanse Humankind.