A treasure hunter has found about 52,500 Roman coins, one of the largest such finds ever in Britain, officials said Thursday. The hoard, which was valued at 3.3 million pounds ($5 million), includes hundreds of coins bearing the image of Marcus Aurelius Carausius, who seized power in Britain and northern France in the late third century and proclaimed himself emperor. Dave Crisp, a treasure hunter using a metal detector, located the coins in April in a field in southwestern England, according to the Somerset County Council and the Portable Antiquities Scheme. The coins were buried in a large jar about a foot deep and weighed about 160 kilograms in all. The find includes more than 760 coins from the reign of Carausius, the Roman naval officer who seized power in 286 and ruled until he was assassinated in 293.