(Image credit: Mike Pennington, shared under Creative Commons 2.0)

Summary:  Finn and Hengest contains Tolkien's translations of and commentary on two Old English texts - the "Finnesburg Fragment" and a small excerpt from Beowulf.  Both are allusive accounts of the Battle of Finnsburg, a medieval Germanic conflict which we now know about only from Anglo-Saxon poetic sources.  Tolkien's translation and commentary bring the battle to life for modern English readers while proposing solutions to the central mysteries of the texts.

Why should I check out this canon?  Admittedly this is not Tolkien's most accessible work, but if you're interested in seeing his linguistic/philological practice in action, this is for you!  What emerges is a tragic story of betrayal and divided loyalties, broken oaths, and vengeance.  It's also a fascinating text for anyone interested in the history of northern Europe, the origins of England and the mythologising of Englishness, or medieval languages.

Where can I get this?  It isn't the easiest text to get hold of but can be ordered online, either new or second hand - though if you're affiliated to a school or university you may be able to access an online version free of charge through your institution's SSO.  Amazon also offer a digital copy for a few pounds/dollars cheaper than the physical book, if you'd prefer to use an e-reader.

What fanworks already exist?  There are a couple of crossover fics in Russian on AO3, but that's all I could find, so the ground is pretty open!