"Britain was NEVER invaded," strong claim, I realise, but hear me out.
In English History lessons, at schools and colleges, we learn about the first century Roman Invasion of Britain, we learn about the sixth century Anglo-Saxon invasion...but did this really happen?
Evidence (and I'm not going to laboriously cite my sources, but they are valid ones) strongly suggests that both these Historically recorded invasions of our island never took place.
What did happen then?
MERCENARIES happened.
Well, let's not be so commercially crude about this treasonous transaction, let's call them Paid Bovver Boys or Hired Regulators were invited by certain Slum Landlords to clear their land of local invaders or unruly neighbouring tribes. And this happened in both above cited cases of 'invasion'.
In first century Briton, the Atrebates tribe in southern Britain most likely invited the Romans in to regulate for them against the Catuvellauni tribe, giving Rome (and the Vatican) a tactical and theological foothold it had been unable to obtain by forced invasion. Briton became stylised in a Roman fashion, where Britonic tribal leaders adopted Roman fashions and ways, not invaded in the sense we're taught. It's called Hadrians' Wall, but did the still-resident and ruling Britonic Council sanction the work?
In sixth century Briton, Vortigern cited as the Leader of the Britonic Council invited the Anglo-Saxons (who themselves might have been descendants of earlier Romano-Germanic legions in Holland) to regulate against invasions and tribal incursions from the Picts. Here, there's a more stunning revelation, remnants of the Bolivian comet of 592 AD might have cleared out most of the population of eastern/central Briton leaving a gaping geographical void into which the 'invading' Anglo-Saxons eventually moved in larger numbers in the decades that followed. No massacre, no routing, just immigrational opportunism born of simple catastrophe from the skies.
All the while, the south-west of Briton and many parts of Wales/Ireland were doing BUSINESS with sea traders from Turkey and eastern Mediterranean via The Pillars of Hercules i.e. Gibraltar, and have probably been doing so for the last thousand years or more. City of London(sic) still trades the way it used to with and via these long-established global trade routes, except now it's all paper and digital rather than silks and spices trades for tin and copper and lead.
The story of BRITON is opening up to be quite the tale of Not Conquest, but Alliances; financial arrangements, deal making.