Referring to England specifically. Something tells me that they did not speak like a Shakespeare play, as people like to believe they did. Any documents of any sort that accurately portray how they spoke?
A few years ago there was some effort by the folks at the Globe Theatre to put on Shakespeare's plays in what they call the original pronunciation. A video about it can be seen here.
From what they describe there it seems like they mostly arrived at their interpretation by looking at which words rhymed with each other in the poetry of the time, (for example: "Loved" and "proved" were used in rhymes then, but wouldn't be used today).
hi! you'll find several examples in this section of the FAQ, although there are only a few languages in there (mostly English)