Stephen I (ca. 973-1038) was king of Hungary, who went from pagan tribal leader to Christian leader of a powerful nation in the space of one generation and left a remarkable imprint on the history of Europe and the world.

The Hungarian kingdom was established by descendants of Arpad, a Magyar nomad from the steppes of Asia whose horsemen had terrorized central Europe in the first half of the 10th century. After a decisive defeat by the Germans at Lechfeld, just south of Augsburg, Bavaria, in 955, the Magyars, under Arpad's great grandson Taksony, settled down in what is now Hungary.

Taksony's son, the duke Géza, established a semblance of order and initiated moves to Christianize the Magyar/Hungarians by appealing to the Holy Roman Emperor Otto I for Christian missionaries. His move has been termed the "Quedlinburg Mission." Fortunately, for the Hungarians, Otto did not take...