How late was Vulgar Latin spoken in Britain?

[Deleted member 5909]

Pretty much what it says on the tin: What is the general scholarly consensus as to how late a dialect of Vulgar Latin was spoken in Sub-Roman Britain, at least in the more Romanized lowlands?

I’m currently exploring some ideas for a possible TL and was wondering if Vulgar Latin would have been (relatively) widely spoken still by AD 450? How about AD 500?

 

[jocay]

There seems to have been small idolayed pockets like in St. Albans that lasted until the 700s.