The base language was formed by crashing two major European language families into each other a thousand years ago, and we've been happily borrowing words from every other language on Earth ever since as we've needed them. If we want to make up a brand new word, as we so often do in science, we'll probably reach for a handful of Greek and Latin prefixes and suffices and stick them together any way we like.
After a thousand years of this, English is probably the language with the biggest and most expressive vocabulary of any language in the world.
http://mentalfloss.com/article/59320/5-words-are-spelled-wei... has a couple of nice examples.
Obviously (because this is English), the change didn't apply universally, but it applied widely enough to move our pronunciation out of sync with the European languages it was derived from.
See https://en.wikipedia.org/wiki/Great_Vowel_Shift for more detail.
I'd go back to the Roman invasion, at least, and the mixing of Latin as the official language of Roman Britain with the Brytthonic language(s) [themselves already probably mixing with other earlier Celtic tongues].
Some of the Latin in English (and Cymraeg) was adopted via the Norman/French tongue but there's pretty clear evidence -- AFAICT, I'm not a linguist -- of Latin being retained and adopted from the occupation. That presumably gave us a Creole as a starting place to add in Germanic (Saxon, Frisian, Jutlandish), Celtic (Irish, Pictish?), and Nordic languages in the first millennium AD making the mixing of Norman French just more of the same??
So I'd say, "after two thousand years of this" ...
It can be hard to tell the history though, eg sovereign came from French (rein) but got Latinised (regnare) in spelling reform.
One interesting thing for me was finding English loanwords in Cymraeg (former Welsh language) that are no longer used in English. I'll bet there are some French loanwords in English that aren't in French any more?
There are words adopted twice too, https://en.m.wikipedia.org/wiki/List_of_English_words_of_Fre... has lots of examples. Giving us chief and chef in English with different meanings but based on a single French word (I gather) adopted at different times.
I don't know any and I don't think I'll be able to spot them since they aren't in French anymore.
But (from your link), there are words coming from Old French in English which then went back in French, but usually keeping the English pronunciation.
For some reason, it's not half has horrible to listen to broken English. Unless it's by Germans, in which case I usually leave the room. Or drop the class, as it happened during my studies.