Engines of War is a Valyrian scroll written by Ayrmidon. It is rare to find in its entirety. A complete copy can be found in the library of Winterfell.
Books[]
A Game of Thrones[]
During his visit to Winterfell, Tyrion Lannister reads the scroll. He later remarks to Septon Chayle that a complete copy is rare, and so he should take good care over returning it to the shelves.