Visitors to Magna Carta: Law, Liberty, Legacy may have noticed that we have one or two objects on display, in addition to the many manuscripts and documents telling Magna Carta's 800-year-old story.

One of those objects is a double-edged sword, found in the first section of the exhibition, on loan to the British Library from our friends at the British Museum. The item in question was found in the River Witham, Lincolnshire, in July 1825, and was presented to the Royal Archaeological Institute by the registrar to the Bishop of Lincoln. It weighs 1.2 kg (2 lb 10 oz) and measures 964 mm (38 in.) in length and 165 mm (6½ in.) across the hilt; if struck with sufficient force, it could easily have sliced a man’s head in two.

An intriguing feature of this sword is an as yet indecipherable inscription, found along one of its edges and inlaid in gold wire. It has been speculated that this is a religious invocation, since the language is unknown. Can you have a go at trying to decipher it for us? Here's what the inscription seems to read:

+NDXOXCHWDRGHDXORVI+