There are several Documents in Fire Emblem Warriors: Three Hopes that you can find to learn more about each of the three houses: Black Eagles, Blue Lions, and Golden Deer.
These Documents are purely available as collectibles in the game and only offer more lore for you to absorb. They have no impact on the storyline.
The following guide will show you all of the locations of the Documents in FEW: Three Hopes.
FEW: Three Hopes Documents Locations
Black Eagles Documents Locations
Empire Noble I
This is going to be the first Document that you find for Black Eagles. When you are given the objective to speak with Edelgard, head inside the Command Center (or Headquarters) in the camp to find the Empire Noble I Document on the long, feasting table.
Imperial Territories of Adrestia: Book One
Once again, after speaking with Edelgard, make your way to the Church on the northern part of the map. You will find the next Document inside on the altar.
Report on Abyss
The last Document of the Black Eagles can be found by visiting the Item Shopkeeper in the northeastern part of the map. You will find the Document on a pile of crates on the right-hand side of the shop.
Blue Lions Documents Locations
Exquisite Old Letter
This is going to be the first Document that you find for Blue Lions during the Unrest in Fhirdiad objective. When you are given an objective to speak with your classmates, head over to Dedue. There will be a crate nearby with the Document on top.
You will find this Document on the same long table of the Command Center in the center of the camp. However, you will find it after speaking with Dimitri.
Letter from an Abyss Resident
Once you are assigned to speak with Dimitri, head to the Item Shopkeeper in the northeastern part of the map to find the next Document on top of some crates on the right side of the shop.
Golden Deer Document Locations
This is going to be the first Document that you find for Golden Deer. When you are assigned to check out the camp facilities, pay a visit to the Command Center to pick up the Document from the long, feasting table.
Allied Territories of Leicester: Book One
Follow up by visiting the Church in the north once again. The next Document will be in the same place as before, on the altar.
Letter from the Abysskeeper
The last Document of Golden Deer and the game itself can be found on the same crates on the same right-hand side of the Item Shopkeeper.