The Templars, the Hospitallers, the Tuetonic Knights and the Knights of the Spanish and Portuguese orders were 'noblemen vowed to poverty, chastity and obedience, living a monastic life in convents which were at the same time barracks, waging war on the enemies of the Cross'. These military religious orders emerged during the Crusades as Christendom's storm troopers in the savage conflict with Islam. Some of them still exist today, now devoted to charitable works. "The Monks of War" is the first general history of these orders to have appeared since the eighteenth century. Writing in "The Times Literary Supplement", Professor David Knowles described it as, 'Undeniably the work of someone who knows and accepts the standards of critical history, but ...who sees the past also as an epic or a colourful spectacle'.