A hoard of Roman coins believed to have been deposited beneath the ground for security during the dying days of the Roman Empire was among finds declared treasure trove at an inquest yesterday.

The 150 ancient artefacts, which date back to the late 4th or early 5th century, were discovered by metal detecting and geophysics enthusiast Malcolm Weale on farmland at Quidenham on July 1, 2010.

Norfolk coroner William Armstrong said he believed the hoard, which bore an image of emperor Constantine 1, who ruled Britannia, was either lost or deposited during the last days of Roman rule in Britain, possibly in anticipation of impending upheaval and with a view to retrieving the coins at a later date.

He added: 'The coins were clearly deposited or lost together and therefore constitute a hoard. The silver coins are more than 300 years old and they are therefore classed as treasure.'

The hoard is set to be displayed at Norwich Castle museum and was discovered by Mr Weale after he had found coins on other sites nearby and had taken aerial photos of the Quidenham land before conducting the metal detector tests.

Other discoveries included an early medieval silver gilt mount, dating back to the early Carolingian age in the eighth and ninth century, which was found at Roudham, two Iron Age silver units found at Tacolneston, a middle bronze age gold pennanular ring found at Morley and an early medieval biconical gold bead discovered at Witton.

The inquest also heard about the discovery of an early medieval gold coin pendant at North Elmham, believed to date back to the Byzantine era, which bore an inscription of emperor Maurice Tiberius.

The artefact was produced in the south of France.