Bizarro Theater has been ongoing for much longer than the days of 20th century radio, TV and Internet media.
Back in 731 or so, a monk named Bede wrote Historia ecclesiastica gentis Anglorum (An Ecclesiastical History of the English People) in which he spun a tall tale of propaganda about the failings of Roman Christian Britons to convert Germanic immigrants to Catholicism. It is from Bede that modern era historians developed the myth of an invading horde of Angles, Saxons and Jutes sailing an armada across the English Channel coming to conquer and kill off Celto-Britains around 450 AD. After the invasion, myth tellers claim the locals slowly adopted the language, customs and beliefs of the Germanic Angles, Saxons and Jutes.
What invasion? Germanic people likely sailed with Romans in 43 AD and partook in the Roman invasion of Briton. As it were, likely most of the Roman troops of the 43 AD invasion came from Germanic imperial provinces.
Likelier still, Germanic Peregrini from Germania Inferior and Gallia Belgica populated Roman-Britain over the long span between 43 AD and 410 AD along with Roman citizen administrators and soldiers. Likely, these Germanic Peregrini outnumbered Romans emigrating to Britain by a big factor. Also likely, Germanic Peregrini were given enfranchisement maybe even by en bloc and likely had higher status than those of wealh pre-Gaulish origin Britons. As it is, all Germanic Peregrini were made citizen in 210 AD.
These Germanic Peregrini provided the backbone of Roman-standards work in Britain precisely because they had been doing so already in the imperial provinces on the mainland. These Germanic Peregrini likely were skilled craftsman and skilled farmers who were looking to move up to "new world" opportunities.
Perhaps those of the Ubii and Tongres comprised the first Germanic Peregrini who sailed with Roman citizens and soldiers from Lugdunum Batavorum (Katwijk) and Bononia (Boulogne). No doubt Germanic Peregrini of other clans and tribes traveled to the new world to advance themselves. Their population grew with their Britain-living descendants.
Since most administrators and soldiers of the 43 AD invasion came from Germanic imperial provinces, quite likely most of the administrators and higher-ranking soldiers were bi-lingual in government Latin and the prevailing Germanic tongue of their region. This is likely so because likely most were Germanic and not Romans from Rome.
The archaeological record fails to show a mass invasion and wipe out of Britons. It seems so unlikely that 5th century Germanic tribes from Germania Magna had the financial means much less the technological and organizational means to build a flotilla of ships in a World War 2 style mass invasion of Britain. That isn't to say enterprising Germanic mafioso from that region didn't show up in the power vacuum created by departing Roman administrators and soldier-police. According to those at 3D history, an Anglo-Saxon boat could carry around 40. That means an invasion of 100,000 would have needed a whopping 2,500 boats!
The Romans had the sophistication and means. The Romans carried on extensive trade from their provinces. The Romans would have been sailing ships likely on schedule from Lugdunum Batavorum (Katwijk) and Bononia (Boulogne), ships which would have transported new world opportunity seekers. The Romans had transport highways from these ports leading all the way back to Rome.
The linguistic record shows so few words of Celto-Britons in English. Yet more than a few Romano-Latin words in English supports Celto-Brits being sequestered from Romans and Germanic Peregrini.
So likely, the Old English period did not begin around 450 AD as far too many have supposed for far too long. Rather, Old English in Britain likely began 43 AD because people were already speaking a Germanic tongue, which became the basis of misnamed "Anglo-Saxon" by linguists.
That Celto-Britons get labeled as foreigners (wealh) reveals exclusion. The DNA record supports connection between contemporary Englishmen and contemporary North Sea Germanics of Belgium, Netherlands and northern Germany.
What happened in Britain from 43 AD might have looked quite a bit like what happened in Colonial America. Englishmen and Ulster Scots, the Romans and Germanics of later times, pushed out into the hinterlands the native North American "indians", the Celto-Britons of their time. The population of hunter-gatherers would remain small relative to the growing population of sophisticated farmer-traders.
Likely, the next big-scale invasion didn't come to the shores of Britain until 865 AD.
Recently, I came across this BBC doc from a few years ago hosted by Francis Pryor and based on his work Britain A.D. Pryor and I agree on the imaginary Angle, Saxon, Jute invasion. However, it should seem obvious to all that Germanics invaded in 43 A.D. and continued to migrate to Roman Britain for centuries.
Likely, these earlier migrants and their descendants spoke a Germanic tongue that gave rise to the English of the Old English era.
I'd bet the only Saxons to invade Britain were these guys who formed their invasion in Barnsley, South Yorkshire back in 1976.