For starters we are leaving in a fantasy world so history isnt so relevent.
secondly there were a number of secret societies in europe at the time. like http://en.wikipedia.org/wiki/Vehmic_court , a group of men who played judge jury and executioner for people they believed were wrong.
have you really used your brain on this one novicus? its a SECRET society, naturally you wont know of them rofl... isnt that obvious?
this is taken from wiki
"In the Middle Ages, regicide was rare in Western Europe, but it was a recurring theme in the Eastern Roman Empire. Blinding and strangling in the bathtub were the most commonly used procedures. With the Renaissance, tyrannicide—or assassination for personal or political reasons—became more common again in Western Europe. The reigns of King Przemysł II of Poland (1296), William the Silent of the Netherlands (1584), and the French kings Henry III (1589) and Henry IV (1610) ended with assassination. High medieval sources also mention the assassination of king Demetrius Zvonimir (1089), dying at the hands of his own people who objected to a proposition by the Pope to go on a campaign to aid the Byzantines against the Seljuk Turks"
so yes it was rare but it happened.
point1 : get out of your silly fantasy world and read some real history books, it wasnt as pretty and calm as you make out, war and murder was common for knights, they would butcher innocents in the name of there king, ignoring the "code"
in my rp story the king knights me and gives me fiefs, thats my RP and you cant deny it since you arent the king.
point 2. im not a civilian, im a noble.
point 3, The house of fenwick, lotus banner. problem?
edit:
Fact is nobody your going to have to remove 3 of the houses if not more because you believe in a unrealistic fantasy history.
secret orders are secret, if your gullible enough to believe that no noble ever plotted against another you shouldnt be running anything like this.
nobles dont equal knights. im sick of telling you this, if you want to talk about "code" refer to knights or second born nobles.