THE NORMANS were a relatively short-lived cultural and political phenomenon.  They emerged early in the tenth century and had disappeared off the map by the mid-thirteenth century.  Yet in that time they had conquered England, southern Italy and Sicily, and had established outposts in north Africa and in the Levant.

The reality is that, even within this short time span, the Normans changed as time and place dictated from Norse invaders to Frankish crusaders to Byzantine overlords to feudal monarchs.  In the end their contribution to medieval culture was largely as a catalyst for other, older traditions.

Trevor Rowley is an Emeritus Fellow of Kellogg College, Oxford.