The six hundred years after the Romans left Guernsey are known as the Dark Ages. It wasn’t dark, but the world did get colder than it was before. The Huns, the Saxons, the Goths and the Franks came from the East looking for new lands. The Roman Empire fell apart trying to fight these peple they called “barbarians”. Later, Vikings came down from Norway and Sweden to attack the Saxons and Franks once they had settled into new homes.
The Roman army was paid in silver coins. Roman coins had the heads of emperors on them, so when we find them we have a good idea of what date they were lost. If there are no coins, archaeologists find it hard to decide what date a site is. The Romans spent this money in markets on things like fine pottery and amphorae of wine and olive oil. Once there was no more money, what happened to the markets? We find very little pottery after the year 400 and no bricks or tiles from Roman-style houses. It is very hard to know what was happening.

People must have still been living in the Channel Islands once the Romans had gone, but we can’t find them. There are no graves, no houses and no shipwrecks. The Romans used to scratch their names or initials onto things they owned. Roman builders would carve names and dates onto their buildings and onto gravestones. After they left, nothing.
We know a lot about the Roman emperors, generals and famous people as Roman writers wrote history books. Some of these books were copied in the middle ages, so we know a lot about Roman history. The Franks, the Saxons and the Vikings did not write many books. Archaeologists need to work very hard to shine a light on the Dark Ages.