What event changes Prince Michael's life?

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.