Mistakes happen, especially in large books of global history. No book is perfect. The Killing Age is no different.  I employed a fact-checker, but even with the best person errors have a way of finding their way into the finished text. Usually these are small; sometimes that are not. What is perhaps different is this website, which allows me to address errors as I discover them, similar to what one sees in scientific publications.  My commitment throughout is maximum transparency. If you, the reader, discover a mistake and would like to share it with me, please do so!