A British man rewrote medieval history on his lunch break when he unearthed evidence of a previously-unknown Viking king.

Darren Webster, a metal detector enthusiast, stopped by a field near Canforth, northern England, to practice his hobby and uncovered a hoard of silver Viking treasure buried three feet (0.9 meters) below the earth, The (London) Times reported Thursday.

"My machine was telling me that I'd found some kind of silver," Webster said. "So I was slightly disheartened when I saw a lead pot. It was as I was lifting it that silver pieces started falling out of it."

The 201 silver objects -- including 27 coins, 10 arm-rings, six brooch fragments, two finger rings, a fine wire braid and 14 ingots -- were put on display at the British Museum.

Dr. Gareth Williams, the museum's curator of early medieval coins, said the haul probably would fetch a "high five-figure sum."

When the exact value of the silver hoard is calculated next year, Webster will be allowed to keep half of its value under the UK's Treasure Act, with the owner of the field, who wished to remain anonymous, taking the other half.

Most interesting among the haul was one of the coins, which experts believe bears the name of a previously unknown ruler of Northern England. The coin reads "Airedeconut" -- thought to be an attempt to represent the Scandinavian name "Harthacnut," according to some reports.

Other coins in the collection date to the time of Alfred the Great, who reigned 871 to 899.

Researchers now will try to uncover more details about the mysterious king, who would have ruled Northumbria, northeastern England, at a time when the Vikings were settling in Britain and converting to Christianity.

A Viking coin, dated between AD 900 and 910, of a previously unrecorded type believed to carry the name of an otherwise unknown Viking ruler, is displayed with other coins at the British Museum in London.