To the English mix, one needs to add the arrival of North Africans (many of whom were probably the common ancestors of Berbers) which started roughly 200 BC, by encouragement of the Roman ruling class. Therefore, for the millions of people who claim English blood, a good share of them (particularly if they trace back to the Colechester area) have North Africans in the mix.
Colechester's origins actually date back to Ancient Carthage. A century or so after the Romans destroyed Ancient Carthage in the Third Punic War (146 BC), Julius Caesar allowed the city to be rebuilt. By 100 a.d., it had grown to a city of a half million, second only to Rome in size in the western part of the empire.
The decline begin shortly thereafter as the surrounding area begin to turn into desert. The Angles, Picts, Celts and Brits, meanwhile were a rather unruly lot and difficult to rule so the Romans actively encouraged their North African subjects to emigrate, where they founded Colechester.
The old nursery rhyme Old King Cole refers to the king of Colechester who was of North African stock. His blackness, of course, is subject to debate since even a bronze skinned Berber would look black to the fair skinned locals.
But, I digress. As you know, the various groups fought for control of the British Isles until the Normans (yet another group seeded by vikings) came out victorious in the pivotal October 14, 1066 Battle of Hastings. But that still didn't settle the matter completely as the Irish, Scots, Welsh and others will tell you.
BTW, I really enjoy your posts and added knowledge of history, even if I don't always agree. You appear to be very well read on the subject. Is it a professional specialty or just a hobby (like me)?
Regarding the Saxon arrivals in Britain, St. Gildas gives us the dates ~ he was there when King Ad gave up the family farm (then Northern Cornwall, now Wessex/Essex/Susses/etceterex) to the Saxons ~ who we now know weren't all that numerous. The residents relocated to a recently depopulated Brittany.
The depopulation occurs after the end of the world event ~ and involves Merlin et al replanting grapes from there to the Rhone Valley.
That would be about 535AD give a couple of decades.
At the same time the Angles were still waiting in Freisland ~ their relocation to Britain happened later, and they began moving into a quite miserable Scandinavia and West towards Nederland and Britain.
The Vikings arise several centuries later in Scandinavia after they'd overextended themselves and were starving to death. Life was very difficult until they got their seagoing boats ~ in the 800s. By then their society had deteriorated into a dog eat dog primitive barbarism ~ with reading and writing.
Most people of Scandinavian ancestry don't like to think of it that way but that's the way it was.
It was 1000 AD before the missionaries got to Iceland to convert those people to Christianity.
Regarding the Berbers, they made the trek out of Europe a very long time ago ~ roughly the same time as the Sa'ami going up the coast to the Arctic ocean. They both have that Sa'ami origin X-factor gene sequence.
That's all a good 14,000 years ago.
Viking stuff is recent history/archaeology.