Get Latin (in a recognizible form, with minimal bastardization) to be the common and official language of many European countries (and subsequent colonies). Your POD has to be after AD 476, and the Roman/Byzantine Empire cannot exist to the present. The Byzantine Empire (though they would likely be speaking Greek anyway) must fall by AD 1453. The countries should be split up pretty much the same as OTL, with major ones analogous to Spain, France, Germany, etc. Not that they can't be more divided, they just shouldn't be more united than that.