At last Doctor Pedro Recio Agilers of Tirteafuera promised to let him have supper that night though it might be in contravention of all the aphorisms of Hippocrates.
…they no doubt had me enchanted; for I swear to thee by the faith of what I am that if I had been able to climb up or dismount, I would have avenged thee in such a way that those braggart thieves would have remembered their freak for ever, even though in so doing I knew that I contravened the laws of chivalry, which, as I have often told thee, do not permit a knight to lay hands on him who is not one, save in case of urgent and great necessity in defence of his own life and person.
…a mistake all this time," answered Don Quixote, "for in truth I thought it was a castle, and not a bad one; but since it appears that it is not a castle but an inn, all that can be done now is that you should excuse the payment, for I cannot contravene the rule of knights-errant, of whom I know as a fact (and up to the present I have read nothing to the contrary) that they never paid for lodging or anything else in the inn where they might be; for any hospitality that might be offered…
Then, Don Quixote being vanquished, the bachelor knight was to command him to return to his village and his house, and not quit it for two years, or until he received further orders from him; all which it was clear Don Quixote would unhesitatingly obey, rather than contravene or fail to observe the laws of chivalry; and during the period of his seclusion he might perhaps forget his folly, or there might be an opportunity of discovering some ready remedy for his madness.
There are no more uses of "contravene" in the book.
Show samples from other sources
This heretical suggestion had been squelched because, as one of Cleburne’s fellow officers said, "its propositions contravene the principles on which we fight."
James M. McPherson -- What They Fought For - 1861-1865
You think you could get me to contravene proper authority because I expressed some little affection?’