A counterfactual, with help from David Crystal
History gave English two invasions in the wrong order for a tidy thought experiment, so it’s worth doing the untidy version. In 1066, French-speaking Normans conquered an England that had already spent two centuries absorbing Norse-speaking Danes. What if the order had been reversed: Normans first, Danes two centuries later?
The answer turns on something David Crystal spends a good deal of The Stories of English getting right: the two invasions didn’t reshape the language in the same way, because Old Norse and Norman French sat at completely different linguistic distances from Old English.
Old Norse was close. Close enough that Norse and Old English speakers in the Danelaw could largely make themselves understood to each other with effort, which meant the languages didn’t just borrow from each other, they fused. That’s why Norse contact left English with core grammar changes (simplified case endings, the third-person plural pronouns ‘they’, ‘them’, ‘their’, all Norse imports replacing native forms) and everyday vocabulary so basic it doesn’t register as foreign: ‘sky’, ‘skin’, ‘leg’, ‘window’, ‘egg’. Words a five-year-old uses. That’s fusion, not borrowing.
Norman French was distant. Structurally unrelated enough that fusion wasn’t really on the table; what happened instead was a prestige layer laid over an already-settled grammatical base. French gave English an enormous vocabulary of law, government, cuisine, and high culture (‘justice’, ‘parliament’, ‘beef’, ‘sovereign’), almost entirely as loanwords sitting on top of Old English grammar rather than reshaping it. The peasant kept ‘cow’ and ‘pig’; the word for the meat on the aristocrat’s plate became ‘beef’ and ‘pork’. That split alone tells you which contact event fused and which one layered.
So: swap the order. Put the Normans first, arriving to conquer an Old English still close to its Germanic roots, its case system intact, no Norse fusion yet to soften the grammar. French sits down on top the same way it did historically, prestige vocabulary over a native grammatical base, but the base it’s sitting on hasn’t yet been simplified by two centuries of Norse contact. Grammatically fussier English, probably holding onto more of its case endings for longer, since nothing has yet done the work Norse actually did in loosening it.
Then, two centuries later, the Danes arrive into an England already saturated with Norman French prestige vocabulary and already governed in French-descended institutional language. Does Norse still fuse the way it did? Probably not as thoroughly. Fusion happened partly because Norse arrived into a relatively unstratified Old English with no competing prestige layer already occupying the register Norse might have filled. Arriving second, into a linguistic hierarchy already settled around French at the top and English at the bottom, Norse likely gets pushed into something closer to what French actually became: a loanword layer, not a grammatical rewiring. English keeps more of its inflectional endings. ‘They/them/their’ might never happen; we might still be using descendants of Old English ‘hie’.
The genuinely counterintuitive conclusion: reversing the order wouldn’t just delay the same outcome, it would produce a structurally different language, because which contact event gets to fuse and which gets relegated to borrowing depends on which language arrives into unstratified ground first. Order isn’t incidental to the outcome. It’s most of the outcome.
None of which changes how any of this gets taught, except as a reminder that the ‘rules’ a C1 student is memorising were never inevitable. They’re the accumulated residue of which invasion happened to arrive second.