Here are some primary sources.
The Art of War
by Machiavelli from 1520.
For personal combat/Martial Arts, try
*Kunst des Fechtens/Art of Combat
by Joachim Meyer from 1570- Joachim Meyer
by Achille Marozzo from 1536- Achille Marozzo
*Paulus Hecter Mair's fechtbucher. 1550's There is a museum file online with the book but i cannot find it now.