Below is a list of books that I heartily recommend in their entirety. I have taken excerpts from several of them, but many of their best parts are lost out of context.
You will not find any hyperlinks to online booksellers; my purpose here is education and enjoyment. I instead recommend your local public library. What books they do not have they can borrow for you via the Interlibrary Loan program.
A Distant Mirror: The Calamitous Fourteenth Century by Barbara W. Tuchman.
Blood Rites: Origins and History of the Passions of War by Barbara Ehrenreich.
Dreadnought: Britain, Germany, and the Coming of the Great War by Robert K. Massie.
The Gifts of the Jews: How a Tribe of Desert Nomads Changed the Way Everyone Thinks and Feels by Thomas Cahill.
Inventing the Middle Ages: The Lives, Works, and Ideas of the Great Medievalists of the Twentieth Century by Norman F. Cantor.
Lies My Teacher Told Me: Everything Your American History Textbook Got Wrong by James W. Loewen.
The Martial Artist’s Book of Five Rings by Miyamoto Musashi, translated by Stephen F. Kaufman.
The Mask of Command by John Keegan.
The Quest for El Cid by Richard Fletcher.
Real Magic: An Introductory Treatise on the Basic Principles of Yellow Magic (Revised) by Isaac Bonewits.
Saladin In His Time by P. H. Newby.
Sensei by John Donohue.
Zen in the Martial Arts by Joe Hyams.