John Sadler was born and bred in Northumberland and he has worked for most of his career in the law. He is an expert on medieval warfare and a prolific writer on the subject. He has made a particular study of the history of conflict between England and Scotland. His many books include Battle for Northumbria, Scottish Battles, War in the North 1461-1464, Border Fury: The Three Hundred Years War, Clan Donald's Greatest Defeat: The Battle of Harlaw 1411, Flodden 1513, The Battle for Crete 1941, Culloden 1746, Bannockburn: Battle for Liberty and The Second Barons' War: Simon de Montfort and the Battles of Lewes and Evesham.
