Book excerpt: The third of a projected seven volumes, this book presents the glory of the High Middle Ages; the flowering of Christian civilization which produced Saints and heroes, Popes, kings and queens, philosophers and architects whose achievements glow like beacons across the centuries. This was the age of united and triumphant Christendom - the age of St. Bernard of Clairvaux, St. Francis of Assisi, St. Dominic, and St. Catherine of Siena; of St. Thomas Aquinas and the Gothic cathedrals; of the crusading kings Richard the Lion-Heart and St. Louis IX.