In the foreword to his textbook Algebra, Serge Lang writes (on page vi)
I have frequently committed the crime of lèse-Bourbaki by repeating short arguments or definitions to make certain sections or chapters logically independent of each other.
What does “the crime of lèse-Bourbaki” mean? I do not understand French, so naturally I googled the phrase and what turned up was the Wikipedia page for lèse-majesté.
Lèse-majesté is the crime of violating majesty, an offence against the dignity of the reigning sovereign or against a state.
I am aware that Nicolas Bourbaki is a pseudonym used by a group of influential French mathematicians who wrote a series of textbooks in a terse and formal manner. So, is Lang honoring Bourbaki by equating them with (mathematical) royalty?
I don’t think it was honoring Bourbaki, but rather gently mocking them.
As stated in the comments and other answers, the Bourbaki group was known for its lack of redundancy : if you read the books, you see they never repeat definitions or arguments, instead they always refer to previously written books with a concise and cold reference (I don’t have the format in mind but it’ll be something like [Book 5, Ch.6, S.5, §4.3])
Lang is saying he will not do this and he coined the term lèse-Bourbaki. In doing so (if I’m not mistaken, he’s a French speaker, and so he’s not making a mistake in the use of this image) he’s not equating them with royalty, but rather implying that they see themselves as such or that others see them as such: he’s gently mocking the status of Bourbaki (which was in a sense the status of royalty, back in the days, at least in France).
I’m saying this because, as a native French speaker, I know how and why French speakers use phrases relating to kings and queens: we use them to disqualify people, rather than honor them. When a child throws a tantrum because s.he is denied something s.he wanted, it’s not rare (of course you don’t hear it all the time) to hear his/her parents refer to their child as a king or queen, and tell him/her jokingly that they were just victim of a “crime de lèse-majesté”.
As a French speaker, this is what I understand from this quote (and again, Lang was himself a French speaker if I’m not mistaken): it’s not as bad as a child’s tantrum but you can certainly imagine Lang with a wry smile while writing this. So to answer your question in the comments, it’s definitely related to “lèse-majesté”, but it’s very likely not to honor Bourbaki.
(Note that the habit of using phrases and sentences relating to kings/queens mostly as derogative is very common in France and is probably a heritage of our many revolutions and continued failures to attain a democracy)