Fun fact: it still is!
The formal process for the passage of bills in Parliament uses Norman French phrases - "La Reyne le veult" ("The Queen wishes it") being the most widely known as it is used during prorogation to signify that royal assent has been given to a bill to make it an Act of Parliament.
Similarly, bills transmitted between the two houses of Parliament are sent with Norman French phrases.
The related cultural overhang is twofold: the english barony probably welcomed the divergence. yes, they wanted to seem posh in french speaking lands, but they had to deny any french right to english (norman) lands. Also, the law demanded that a lot of terms be defined in french and "not french" to ensure there was no ambiguity.
Thus "without let or hindrance" and the other "legal doublets" many of which are bridging the gap as english became dominant.
For murder:
That [the defendant] did feloniously, wilfully and of his Malice aforethought kill and murder [the deceased]
For manslaughter:
That [the defendant] did feloniously kill and slay [the deceased]
In this case, "kill", "murder" and "slay" are all Germanic words, though "murder" may have gone into French and then back into English, which is why it has the extra R compared to German "Mord" and Dutch "moord".
Which is a somewhat more positive way of saying that they rhyme with the wrong enunciation. Which is a totally valid way to construct lyrics in music - you have a bit of artistic leeway and the exact "correct" pronunciation isn't exactly important - but it's probably not too helpful for a listener who's trying to work out how those words were actually spoken in conversation.
That said, I'd be far more concerned about a future linguist discovering Prisencolinensinainciusol.
Greek has Demotic and Katharevousa. Louis de Bernieres writes in "Captain Correli's mandolin" implying that the English officers in ww2 sounded to the Greek peasantry like Shakespearean actors, all taught Greek in boarding school, but only speaking "high" Katharevousa Greek, not the common Demotic. He does this by using archaic English writing.
English code switching .. is that really that different yo? Yeet me out of here. Valley girl speak.. the list of dialect and pronunciation in contemporary US culture of the last 50 years is immense.
I bet that without a relatively large amount of exposure they can’t and then suddenly it’s really obvious what the other person is saying. That’s my experience listening to Nigerian English. Didn’t realise the guy working next to me was speaking English with his compatriot for two weeks and then suddenly I understood. Written Portuguese and Spanish are very similar, like Norwegian and Danish levels of similar, or Scots and English.
There are lots of different dialects and accents in the UK, let alone the US. AAVE for example is as legitimate a dialect of English as General American. Bush, Trump and Sanders all speak "American English" yet they sound very different because of their regional accents even before you get into personal quirks.
There's no singular "correct" pronunciation today and there certainly wasn't one in medieval England. We just have "standard" pronunciations based on a rough approximation to one arbitrary dialect we decided to treat as the reference point.
Yes there is. If a linguist a century from now claims that English speakers in 2021 pronounced "car" the same way they pronounced "book", they would be wrong.
Similarly, if they looked at one 2chainz song and concluded that in spoken word "pyjama" and "lasagna" rhymed, that would be wrong. Less obviously so, but wrong nonetheless.
The absence of a singular correct pronunciation doesn't diminish the infinite number of incorrect ones. Even the most ardent of descriptivists think that accepting a pronunciation based off of a single occurrence is somewhat taking the piss.
"Slant rhymes" like this have been used throughout history. Shakespeare is known to have used them in some places: some of his rhymes aren't consistent through his works.
It does help that sound change isn't arbitrary. When one sound changes, other sounds change as well. An entire category of consonants may lose or gain voicing, or shift in point of articulation. When one vowel changes to another, a lot of words can become homonyms, so usually every single vowel changes at once. These are called Chain Shifts:
https://en.wikipedia.org/wiki/Chain_shift
So a single instance of a rhyme is a weak piece of evidence, but when you take into account all of the texts at the time -- and the texts from surrounding times, both before and after -- you can make a good hypothesis. That hypothesis can then be tested against future discoveries, and modify as appropriate.
That's why all Proto Indo European reconstructions are marked with an * to say "We've never actually heard this word so we don't know if anybody ever said it". They're aware that all hypotheses are tentative. But that's how progress is made.
English history has kind of retroactively claimed them as being English, but they were not, and we miss out on all kinds of interesting dynamics of the politics of the period if we think of them as being English.
Of course, William/Guillaume is originally the Norse name Vilhjalmr (the same as the German Wilhelm). While the two elements Wil and Helm exist in Old English names (as in Wilfrid or Anselm), there is no evidence of any Old English name that combines them. Old English sources call the Conqueror "Willelm".
Of course, it's all pretty pedantic, given we are talking about names in Old English and Old French, and an Old French name is as removed from a modern French one as it is from an Old English one, so naming these figures with their modern equivalents for the modern reader makes sense too.
I just like reminding myself these early English monarchs were not, in fact, English, and would not be, and would not consider themselves as such, for a while. It also emphasizes how much of a relatively unimportant adjunct of their French lands the Angevins considered England.
It's a very learned parrot!
Especially "cage" and "beke" are pronounced like you'd do in Dutch nowadays, showing the large shift English 'a' and 'e' have undergone.
It sounds lovely, and I would like to imagine it sounding like that - but I don't see how we can reconstruct its pronunciation reliably over 500 years later.
WS Allen in his book, Vox Latina, actually explains how Latin might have been pronounced in the Roman period. Interestingly his theories have universal acceptance today.
Rhyming lines in poetry are a great way to constrain what the various phonemes were. The meter is also a great way to back out what sounds were silent and which were not. (Speaking of which I disagree with the video's choice to pronounce a lot of the final "-e"s in words; that's a trait of early Middle English that was already on its way out by the time of Chaucer and its pretty clear from certain rhyme choices that it's silent in a lot of Skelton's words: see how e.g. Skelton rhymes "Jerusalem" with "creme" and how everything is nice iambs, unless you start pronouncing "-e"s everywhere).
500 years is also within a time horizon where you can get pretty reliable internal reconstruction clues (examining inconsistencies in modern English and thinking about what common features might have led to those inconsistencies) to try to get a better grasp of the phonemic inventory of a language.
Spelling also is a great clue into what the phonemes of the language were (although this is complicated by digraphs and trigraphs).
Then you can use a variety of methods to try to get an idea of what the phonetic realizations of those phonemes were. In this poem in particular we have English words rhymed with foreign words which is a great clue. You can also compare different dialects of English to try to figure out what the original sound is of a word that has now fractured into many different pronunciations.
And of course you can examine what people of the time say about the pronunciation of their own language (this is how we e.g. are pretty confident in r being a trill or a tap, based on descriptions from both domestic and foreign speakers, see e.g. https://english.stackexchange.com/questions/298566/why-and-w... for a great summary of some of the evidence).
All in all it's kind of like playing a game of Sudoku. Rhyming and other clues can set up a set of relationships among different sounds and what would seem like an otherwise sparse set of clues (a comment by some writer here, a common misspelling there, some translation here) can cause cascades of phonetic realizations of different phonemes that magnify the impact of those clues.
And the sanity check to make sure that all this makes sense is being able to provide reconstructed sounds that are consistent with new descriptions, rhyming patterns, and foreign transcriptions as new evidence rolls in over time.
[1] incidentally, one does sometimes hear things like "er ist am kommen" (lit. "he is at coming"). Is this a new development, and is it a borrowing from English?
You may find watching such YouTube videos produces good algorithm recommendations, and also it may lead you to associated subreddit and Discord communities that you may find helpful
It's definitely worth reading through the top questions on those two stacks, but sadly it's not an activity that will occupy you for very long.
https://historyofenglishpodcast.com/
The host frequently speaks archaic forms of English with correct pronunciation.
It's also one of the highest-quality podcasts I listen to. It's very information-dense and each episode is exceptionally well-organised.
I remember when he said it was going to be about 100 episodes, though. #147 came out today and he's at about the year 1500.