[@Archangel89] You don't have to. You could always use existing Houses, like Hawke or Highborn in Falke, or Reigncliff, Taimor, Crosland, Larson, Welm and Morok in Ethora. Or if you'd like, you don't necessarily have to be from a noble family or from a "House" necessarily. The monks have chosen these "knights" because they are either famous, well-respected, skilled, or all of the above. If you character is generally well-regarded, famous, or very skilled in what they do, that could be enough to attract the attention of the monks. So low-born people are also likely to be called.

So really it's up to you. If you do decide to use an existing house, let me know and I can provide you with some more information on them. But also feel free to make up your own background about them too, as long as they don't interfere with anything established. 

[@Sedjwick] It doesn't include your character. I'm only going by those approved. So I included my own two, Drostan Welm, Kace, and Ashe. I think there's a few others potentially working on characters too. Looking forward to yours!