C. V. Wedgwood: The Thirty Years War (New York Review Books Classics)
Edward Gibbon: The Decline and Fall of the Roman Empire: Volumes 1-3 (Everyman's Library)
Richard S. Dunn: The Age of Religious Wars, 1559-1715 (Norton History of Modern Europe)
Stephen O'Shea: The Perfect Heresy: The Life and Death of the Cathars