Evolving English, an exhibition at the British Library.
Actually, this felt a bit like two exhibitions. The first, smaller room was about the emergence of Old English, and then its evolution into Middle English - illustrated by stuff mostly (I assume) from the Library's own collections. This was where one got to see an ivory plaque carved with ancient runes, the original manuscript of Beowulf, samples of Henry V's handwriting (apparently he was the first English king to send letters in English), an Anglo-Saxon Chronicle... Little things like that. A small exhibition, but kind of in-your-face seriously impressive.
Then there was the second, larger room, which was less chronological and more thematic, full of relatively recent texts and manuscripts and sound recordings playing over headphones. I mean, Tyndale Bibles and Caxton printed books (and copies of Viz and John Betjeman manuscripts and "Murder on the Dancefloor" as allegedly the first pop hit to be sung in pure RP), to be sure, but less sense of mists-of-time depth than the first room. On the other hand, it was fascinating stuff; see the Web page for some of the star items. The Shakespeare texts read in what is believed to be period style (i.e. kind of West Country rural) were fun, certainly; the bit of King Lear was oddly less disconcerting than "Now is the winter of ooor discontant.." Nicely presented, too, even if one of the two screens playing TV and radio comedy as examples of the way English can be used was on the blink. (So I had to wait awhile to see Fourcandles and the Goons.)
Anyway, generally recommended if you're in London in the next few months.