First of all, there is such a thing as a magnet fisherman: ie, someone who uses a powerful neodymium magnet on a rope to retrieve metal objects from bodies of water. I did not know this. Secondly, magnet fisherman Trevor Penny pulled up an intact Viking sword from the River Cherwell in West Oxfordshire last November.

Magnet fishing usually pulls up relatively modern debris — tire rims, keys, bicycles, unexploded ordnance — not iron swords hundreds of years old. Penny didn’t know what it was at first, but after consulting with friends and knowledgeable acquaintances, he called it in to the Portable Antiquities Scheme finds liaison officer in Standlake. The finds liaison officer identified it as a Viking sword dating to between 850 and 975 A.D. It is the oldest object ever discovered in Oxfordshire by magnet fishing.

It looks like a Petersen Type M to my untutored eye, based on the hilt shaped like a capital I, the long blade and the date range. Type M swords in good condition can retain traces of organic remains (wood, leather, cloth) on the grip, so it’s important that this sword be carefully conserved. It is corroded, but there could be organic treasure hiding underneath that crusty exterior. Thankfully, the sword is already in the hands of museum professionals and will remain there.

Mr Penny confirmed that it will be retained by Oxford museum services and will either stay in Witney or be put on display in a museum.

He added: “There was a little dispute with the landowner and the rivers trust who don’t permit magnet fishing. The latter sent a legal document saying they wouldn’t take action on the condition the sword was passed to a museum, which I had done.”