The 5,251 silver coins in "superb condition" were found in a farmer's field near Aylesbury in Buckinghamshire. They are said to form one of the largest hoards of Anglo Saxon coins ever found in Britain.
The dig was organised by the Weekend Wanderers Detecting Club in December and was attended by more than 100 people.
The person who made the discovery could split the takings with the land owner if and when the coins are sold.
The perfectly preserved pieces, which feature the faces of Anglo Saxon kings, were in a lead bucket that was buried two feet underground, The Telegraph reported.
Experts said the extremely rare pieces could be worth more than 1 million pounds.
The haul is said to be in "superb condition" and includes coins from the reigns of Ethelred the Unready (978-1016 AD) and Canute (1016-1035 AD).
"This is one of the largest hoards of Anglo Saxon coins ever found in Britain," a Bucks County Museum spokesman said.
Anglo-Saxon England refers to the period of the history of roughly the part of Great Britain that became known as England, during the 5th to 11th centuries.