The Romans leave Britain
In 410 AD the Roman emperor Hornorious wrote a letter telling Britain Roman soldiers to defend the Roman soldiers in Rome as they were being attacked by vicious barbarians. Without these soldiers to defend Britain, the Anglo-Saxons would be able to cross the North Sea from the Scandinavia , Germany and Holland. Therefore Britain became theirs.
Roman life crumbles
Britain didn't just lose the Roman soldiers. The money that had poured into Britain to pay the Roman soldiers' wages also stopped arriving . By 411 AD hardly any new coins were made, so simply the money just ran out. No could afford to for workers to rebuild their creations and work shops didn't have enough enough money to stay there so they vanished .
All of the luxuries of Roman Britain went away. The mosaics the Roman had made were dug into to make hearths for fires and the old buildings had been crumbled into ruins therefore they were ruined and replaced with wooden homes.
But life went on
Many farms and towns struggled bit they learnt to cope with it. The new houses were made out of wood and the was made out of wattle and daub (sticks and wood plastered with mud and dung.) instead of stone (that the Romans used.) The Roman bathhouses and amphitheatres were no longer part of life and houses were built of these building as they had crumbled into disrepair as no one looked after them. But not everything the Romans invented had gone because the vicars and the highest levels of society still spoke Latin which the Romans spoke in.