And then the Saxons (with their metal detectors) sailed in and found that
the Romano-Brits were living in their villas in civilised opulence (with a
little bit of decadence thrown in) and the Saxons wanted to trade and
settle on this green and pleasant land, but the Romano-Brits would not give
them a fair price for their goods, and furthermore in accordance with the
Roman tradition they wanted to tax the grain crops without providing the
military infrastructure and services commeserate with the taxation. The
Saxons rebelled and took up arms against the tyrants.
As I said it is fiction. Being interested in the local history, it really
is a shame that the removal of evidence has meant that the local records
are incomplete. Coins were being sold by the bucket loads before metal
detectors were ever used and nobody much recorded the details.