The story begins in the Chestry Valley of Hungary in 1936, when a prince is born to the old and illustrious Chestry family, princes of the valley since the time of King Stephen, the first monarch of Hungary. Nana, a peasant girl from the village, cares for the young Prince Michael. The outbreak of World War II disrupts Michael's idyllic life when Nazis occupy the castle. In 1944 an Allied air raid destroys the castle, and Michael, ill and suffering from amnesia, becomes a refugee in a hospital for war orphans.

Tom Brown, a friendly American soldier, finds him there and arranges for Michael to come to America, where he settles on the Browns' dairy farm in upstate New York. The second part of the story describes Michael's gradual adjustment to American life after the Browns adopt him.