D&D 5E Help with Nentir Vale adventure

[Eltab]

More background material (from IRL) you might like:
Winston Churchill's "History of the English-Speaking Peoples" has a chapter covering the fall of the Roman province of Brittania, and the permanent arrival of the Angles & Saxons.
Thomas Cahill's "How the Irish Saved Civilization" describes St Patrick's life during the generation after that.

A well-stocked Public Library certainly has the former book, and might be able to borrow the latter book for you.

 

[aco175]

You should also try and get a 2nd hand 4e DMG. I still use the chapter of Fallcrest and Nentir Vale. It is a whole town described in detail and several plot hooks. I would buy a remake of this chapter for 5e.