I know there were a bunch of Germanic invasions, but God knows these weren't the only barbarian opportunists taking advantage of the collapse of Rome. French held on in France, Romanian in Romania, but in Britain we get...English. Was the language of these Angles and Saxons and Jutes modified at all by Latin (before its second coming with the Normans)?
As someone who is a frequent contributor to the FAQ threads on this subject, it's always been my persistent understanding from the literature that Britain had incomplete Romanization, so only the elites spoke Latin/Romance, whereas the rural population continued to speak Brythonic. My presumption as to the reasons for the difference between Britain and the comparative situation in Roman Gaul being the far more frequent occurrence of "urbanized" settlements in Gaul that pre-dated Roman conquest (this not being the case in Celtic Britain) and southern Gaul's existing integration into the trade network. But because the native population spoke Brythonic as Romano-Brits, and the collapse of lowland Roman society so complete, they readily adopted English language as they shifted in identity toward the incoming Anglo-Saxon migrants.
However, I recently read a book by noted early medieval historian Guy Halsall that proposed that no such separation from continental trends existed, and that in fact, lowland Britain also spoke a Romance language. His evidence was that the amount of latin in english languages is on par percentage wise as the amount of latin in celtic/brythonic languages, and that the lack of Brythonic into English is an example of there being no such crossover in time. That is to say that one culture can not simply overtake another culture without some linguistic crossover. The critical part of his argument is his proposal that the latin language importation into english was NOT as a result of the Augustine mission, but the result of existing romance speaking from the significantly-more-than-proposed romanized lowland britain population.
And that an alternate reading of the records of the Augustine mission is that it was written specifically because the fiction of a "pure" catholic conversion from a countryside of English pagans was preferable to the reality of conversion from a countryside of mixed Celtic Christians and English pagans.
Now as of currently, I don't know how accepted Halsall's ideas are, although Halsall is a very respected historian, so his suggestions aren't just some random dude's musings. But I include both options because it would suggest as a possibility, that Britain was home to a Romance language very briefly, and that its demise is due to the collapse of elite participation in church politics, which is the real difference between Anglo-Saxon England and Frankish Gaul (thank you for the explanation /u/georgiusflorentius, wherever you are).
In politically unitary Catholic Francia, the church (and thus church latin) continued to play a predominate role in elite Frankish politics. Whereas in the politically and "ethnically" fractured British island, the church had only a marginal role and was in competition with other religions as means of legitimation. Which meant Gaul was able to have 200 years of relatively unitary societal, cultural, and religious continuation from which to merge the frankish language toward the romance, whereas Britain did not.
Source:
Esmonde-Cleary A.S. The Ending of Roman Britain. Savage, MD: Barnes & Noble, 1990. Print.
Halsall, Guy. Worlds of Arthur: Facts & Fictions of the Dark Ages. Oxford: Oxford UP, 2013. Print.
You might have some luck looking through the many times this has been asked before, or the section in the FAQ.