I am researching and wondering about language and dialect across Britain during the late Anglo-Saxon period (my book takes place in 975). How much were, for example, the Anglo-Saxons and the Vikings able to communicate directly, or did they require interpreters (which is to say how much similarity remained between Old Norse and Old English?) Do we know how Harald and Eadgar communicated?

I assume that since the Scots settlement of the Lowlands didn’t occur until the 5th century that speakers of Scots Gàídhlig and Irish Gaeilge would still have been able to chat fairly easily. Pictish, according to what I’ve read, died out by the 10th century—what were the Highlanders speaking then? Scots, I guess, except for the Norn speakers on the islands?

Welsh, Cornish and Breton branched off from Gaelic pretty early, would Gaelic speakers have been able to converse with Welsh? Probably not. What about Anglo-Saxons? When Alfred brought scholars from Wales in as part of his literacy program, were the Welsh multi-lingual? Would this have been true of ordinary people, traders, soldiers, as well as scholars?

Was Latin the language of diplomacy as well as of the Church? What about traders—you’ve got a lot of back-and-forth between the Continent and Britain, even very early in the A-S period, as evidenced by grave-goods and other archaeology. And speaking of the Continent, by 1066 the Normans are speaking Old French, which is a Romance language. What happened to Gaulish, which was a Celtic language? Apparently it was absorbed into Latin even before Latin morphed into French? (The story is that Caesar sent a message back to Quintus in Greek because Gaulish was close enough to Latin that the messenger would have been able to read it—this despite Gaulish being a Celtic language.) And the Franks were Germanic. How “French” was the language of Charlemagne? And were the Anglo-saxons able to understand any of the speech of the advancing Normans? (Not that the Normans showed any inclination to discuss options . . .)

Good information sources:

Indo-European lanuages, particularly good on Celtic: http://www.peak.org/~jeremy/dictionary/chapters/history.php

Scots:
http://www.ltscotland.org.uk/5to14/specialfocus/scots/background/languages.asp

Welsh:
http://users.comlab.ox.ac.uk/geraint.jones/about.welsh/

Gaulish:
http://arts.uwaterloo.ca/~lcurchin/light/gallica.html

French:
http://en.wikipedia.org/wiki/Old_French

(Actually the wikipedia pages on most of the old language discussions are very interesting)