 full title "Black Book of the Admiralty - Monumenta Juridica Charter of Oleron of the Judgments" for only $70.
Oath of the King of Arms
as quoted from The Black Book of the Admiralty
in original Middle English
"You shall swear by the oath the you received when you were made a herald, and by the faith that you owe to the king, our sovereign lord, whose arms you bear, that you shall truly keep such things as are comprised in the articles following:
"1st, whensoever the king shall command you to give any message to any other king, prince, state, or any other person out of this his realm, or to any person of whatever state, condition, or degree he be of within the same, that you shall do it as honorably and truly as your will and reason can serve you, and greatly to the advantage of our sovereign lord and his realm, and truly report bring again to his highness of your message and as near to the charge to you committed in words and in substance, as your said reason may attain to, always keeping yourself secret for any manner motion, save to such persons as you be commanded to utter your charge unto.
"2ndly, you shall do your true duty to be every day more cunning than others in the office of arms, so as you may be better furnished to teach others under you, and execute with more wisdom and more eloquence such charges as your sovereign lord and his realm or of his realm any nobleman shall lay unto you by the virtue of the office, which his highness will erect you to at this time, discovering in no wise that you have in charge to keep closer than that be predjudicial to the king our sovereign lord and his realm.
"3rdly, you shall do your diligence to have knowledge of all the nobles and gentlemen within your march, which should bear coats in the field in the service of our sovereign lord, his lieutenants, officers, and commisaries, and them with their issue truly register, and such arms as they bear, with the difference due in the arms to be given, and they hold any service by knight's fee, whereby they should give to the king service for the defence of his land.
"4thly, you shall not be unwilling to teach pursuivants or heralds, nor to ease them in such doubts as they shall move to you, and such as cannot be eased by you, you shall show to the constable, and if any pursuivant asks any doubt of you, you shall ask him first, whether he has desired any of the heralds to instruct him in the same, and, if he says, you, you shall limit him one of them, or else ease him if you can. Also, you shall keep, from month to month, in your marches, your chapters to the increase of cunning in the office of arms, and the doubts that there cannot be eased, you shall move to the constable.
"5thly, you shall observe and keep to your cunning and power all such oaths as you made when you were created a herald, to the honor and worship of noblesse and integrity of living, namely, in eschewing disreputable places and people, and always more ready to excuse than to blame any noble person, unless than you be charged to say the truth by the king, his constable, and marshal, or in any place judicial. Also you shall permit truly to register all acts of honor in manner and form as they be done, as forsooth as power and cunning may extend, etc."
Briefly interpreted, a King of Arms shall:
Firstly, Do work well, and keep his mouth shut when not in the company of your king or his men.
Secondly, Be better than the best.
Thirdly, Know his enemies better than he know himself.
Fourthly, Be a mentor, change a life.
Fifthly, We are an elite secret society; don't tell anybody else what you have learned from us.