The 300-coin hoard and its priceless jewellery dated to around the ninth century, when Alfred the Great, then just King of Wessex, fought a series of battles against the Vikings.
Probably buried by the retreating Vikings, the trove was dug up 1,100 years later by metal detectorists George Powell, 38, and Layton Davies, 51, on farmland near Leominster in 2015.
The pair have now been convicted at Worcester Crown Court of stealing the find, illegally concealing it from the authorities and then selling off coins to private collectors.
A jury also found two other men, 60-year-old Paul Wells and Simon Wicks, 57, guilty of conspiring to conceal the hoard. Wicks was also found guilty of helping sell off the coins for cash. They will be sentenced later.
Dr Gareth Williams, of the British Museum, said: “It is not just the theft of the objects that is important in this case.
"It is the fact that the knowledge has effectively been stolen from everyone.
"It dates from after, I would say, Alfred has got that new ambition of being king of the Angles and the Saxons.
“You could say it’s the first hoard of this newly United Kingdom that would later become Anglo-Saxon.”