Wilson's narrative considers everything from weapons development to recruitment to battlefield strategy. Germans' military impact on the rest of Europe has been immense.

If there is one constant it has been the sense of being beset by seemingly more powerful enemies - France or Russia or Turkey - and the need to strike a rapid knockout blow to ensure a favourable result. Almost inevitably, this has in practice meant protracted, relentless and often unwinnable wars, and - in 1939-1945 - moral catastrophe. The author of definitive books on the Holy Roman Empire and the Thirty Years War, Peter Wilson has with Iron and Blood written his masterpiece.