Thousands of knights and foot soldiers are mustering in Venice for the launch of the fourth Crusade. Among them in young Arthur de Caldicot, soon to dubbed a knight. He is thrilled to be part of this huge gathering; but all too soon the crusade falls into disarray.

War, romance, murder, family quarrels, power politics, the conflict between Christianity and Islam: all these are elements in an action-packed story that gives us a startlingly vivid picture of medieval life, enriched by earthy comedy and the magic of the Arthurian legends.