Heaviest gold hoard

The largest documented cache of buried gold is the Trier Hoard, discovered by metal detectorists in the spoil from a construction site in Trier, Rhineland-Palatinate, Germany, on 9 September 1993. The hoard consists of 2,518 solid-gold Roman aurei coins, with a total weight of around 18.5 kg (41 lb) that were buried in 196 CE. The coins were originally wrapped in cloth and placed in a bronze bucket that was buried around 0.5 m (1 ft 7 in) below the floor of a cellar.

It is likely that several larger hoards were uncovered in early-modern Italy, but they were melted down for their metal value soon after discovery and never properly documented. One cache estimated at 120 kg (265 lb) of Roman aurei was found near Brescello, in Reggio Emilia, in 1616. Another, reportedly containing an astonishing 650 kg (1,430 lb) of aurei (approximately 80,000 coins), was found in the same area in 1714.

The Trier Hoard initially made headlines due to the dramatic circumstances surrounding the recovery of the coins. The bronze bucket and its contents were buried on a site on Feldstrasse in the historic centre of Trier, close to the Moselle River and the site of the Roman bridge. In 1993, the site was cleared to build a multi-storey car park for the city's main hospital. At this time, an archaeological team from the Rheinisches Landesmuseum surveyed the site. According to reports, they were working to a very tight schedule and with too few people. Most importantly, they did not use handheld metal detectors as these relatively new devices had not been incorporated into archaeological practice. They made notes of some Roman structural foundations, then had to make way for the heavy construction to begin

On 9 September, an excavator blade sliced through the bronze bucket, taking the top layer of coins with it. The coins were unnoticed and dropped into a truck with several tonnes of earth. The material was then driven to a spoil heap of the outskirts of the city and dumped there.

A group of metal detectorists were waiting at the spoil heap, working over the earth in search of treasure. They immediately started to find coins. A second truckload of material arrived later in the day with yet more gold coins. That night, several men from this group broke into the construction site on Feldstrasse and discovered the rest of the material.

The following night, the detectorist who had recovered the bulk of the material called Karl-Josef Gilles, an archaeologist and curator at the Rheinisches Landesmuseum, and told him what had been found. Over the next few days, the detectorists – who have remained anonymous – dropped off 2,518 coins at the museum. It is believed that the hoard originally consisted of around 2,650 coins with the remainder having either been kept by their founders or left in the ground.

The hoard represented an enormous sum of money at the time of its burial – equal to the annual wages of around 200 Roman soldiers and more than the yearly income of a regional governor. The minting dates of the coins suggest that the hoard was originally buried in 167 CE, around the time of a major typhoid epidemic, and then reopened and added to in 196 CE, during a period of civil war.

Gilles believed that the hoard did not represent the wealth of a private individual, but rather the holdings of some public body, buried by a Roman administrator. In 196 CE, Trier was caught up in the middle of a war between two rival claimants to the title of emperor – Septimus Severus and Clodius Albinus – and was unsuccessfully placed under siege. It is assumed that the person who buried these coins was killed during the conflict, and so never came back to recover the hoard.