Constantine the Great 307-337 AD - treasure trove roman bronze coin with London Mint Mark. On the 22nd of March 1970, a hoard of choice Constantinian Roman bronze coins was found in a field adjoining the Fosse Way, near Bourton-on-the-Water. The locals called the area the ‘Money Ground’ because so many Roman coins were found there over the years. This time they found the ultimate source, what had been an original sack of coins hidden almost 1,700 years ago. Correctly, the hoard was handed in and declared as Treasure Trove. We are thankful to David W. Burge for his excellent article about this hoard, in the Numismatic Chronicle of 1973. It tells you everything you would want to know about the hoard. There were 3,292 coins, all bronze, of which 1,802 were struck in London.