Mr. Treece turns to non fiction in this fascinating and detailed account of the great struggle which is often set down as being a matter of good against evil. After a skillful presentation of the background -- the world of the Mediterranean -- and a careful outline of the religious split between Rome and Constantinople, the author tells the story of the march of the Moslems into the Holy Land where they reigned unchallenged for almost four hundred years while Normans and Danes fought the battles of Europe. It was in the hope of reuniting the Church that Pope Urban II called for a Crusade to support a claimant to the throne of Constantinople and to recapture Palestine. Then comes the savage and tragic yet sometimes heroic story of this ""long act of intolerance"" -- the Crusades of Richard Lion-Heart and St. Louis of France, the Christian destruction of their own Knights Templar, to the last pitiful attempt of Pope Pius II in 1464. Written with insight and humanity, this is a sober approach to what has often been a controversial subject.