This very fine medieval sword, likely forged between 1250 and 1330, was found in the River Witham near Lincoln in eastern England.
Like many swords of that time, it bears an inscription:
But this inscription is particularly obscure, and the British Museum, which owns the sword, has no idea what it means. Inscriptions of this period are often religious. Medieval people had a fondness for Christian formulae of the INRI type, and there are sword incriptions probably mean things like "Saints Michael and George Pray for Me." But this one has defeated the experts, and the museum has put out a call for help, to see if some fan of puzzles and internet research can find the answer.