Experts say the collection of 1,500 gold and silver pieces, which may date to the 7th Century, is unparalleled in size and worth “a seven-figure sum”.
It has been declared treasure by South Staffordshire coroner Andrew Haigh, meaning it belongs to the Crown.
Terry Herbert, who found it on farmland using a metal detector, said it “was what metal detectorists dream of”. It could take more than a year for it to be valued.
The Staffordshire hoard contains about 5kg of gold and 2.5kg of silver, making it far bigger than the Sutton Hoo discovery in 1939 when 1.5kg of Anglo-Saxon gold was found near Woodbridge in Suffolk.
Leslie Webster, former keeper at the British Museum’s Department of Prehistory and Europe, said: “This is going to alter our perceptions of Anglo-Saxon England as radically, if not more so, as the Sutton Hoo discoveries.
“(It is) absolutely the equivalent of finding a new Lindisfarne Gospels or Book of Kells.”
Mr Herbert, 55, of Burntwood in Staffordshire, who has been metal detecting for 18 years, came across the hoard as he searched land belonging to a farmer friend over five days in July. The exact location has not been disclosed.
“I have this phrase that I say sometimes; ‘spirits of yesteryear take me where the coins appear’, but on that day I changed coins to gold,” he said.
“I don’t know why I said it that day but I think somebody was listening and directed me to it.