Britain After Rome, by Fleming.

Anglo Saxons by Marc Morris. Just read that on holiday and loved it. In fact, I lost my copy - leaving it in a hotel - and bought another just to finish it.

This is fiction about the period, but it's fun to read and gives you an understanding of how diverse of a culture existed in the area during that time. The first is a novel called Hild by Nicola Griffith. It's set in the 7th century, before England has been unified and you see the way various cultures are working and competing with each other, the signifiers that different languages hold, and the encroachment of Christianity and it's adaptation with local religions.

The other fun would be the Saxon Chronicles. The TV show The Last Kingdom is based on them. But it shows how the "viking" incursion of England was more of a mix of invasion, trade war, political compromise, and cultural melding.

These are obviously works of fiction that prioritize narrative over hard facts, but both authors did a lot of research and I think in this instance it's helpful to get this kind of exposure to the culture b/c it's so alien from our current conception of England. Almost no one would describe modern England first and foremost as a cultural and linguistic melting pot without an established culture. And although it's not quite true that England didn't have an established culture in the 7th century, things were a lot more in flux. These books help you understand that, and which cultures where struggling to find accommodation within what would become the idea of England in a national sense.

The Great Courses has one called Medieval England. The professor is Paxton, I think. She does a great job and you can listen to it like an audiobook.

It's the age generally known as Anglo-Saxon England (Wales, Cornwall and Yr Hen Ogledd, "the old North", were still Brittonic and Scotland was a mix of Pictish, Brittonic and Gaelic peoples.) The Viking Invasions/settlements of Great Britain and Ireland also happened in this period. That part of history in this part of the world is known in general as the 'Migration Period', the Anglo-Saxon settlement of present-day England being one of those migrations.

A Very Brief Introduction to Roman Britain

A Very Brief Introduction to The Anglo Saxons

A Very Brief Introduction to The Vikings

A Very Brief Introduction to The Normans

All Oxford University Press. Should bracket the period beginning and end (Roman and Norman) and describe the two most notable peoples/systems of the period itself, the Anglo-Saxons and the Vikings.

There are quite a lot of Time Team episodes looking at AS England . Might be a good watch

The Isles by Norman Davies