Kelemen, a citizen of the United States, was born in Budapest, Hungary in 1894, and studied art-history at the universities of Budapest, Munich, and Paris. After four years as an officer in World War I, he continued his work, changing gradually from his original subject, "Impressionism before the Nineteenth Century," to the sources and various manifestations of early Christian art. He worked in the museums of Budapest, Vienna, Berlin, Florence, and London, and made research trips all over Europe. He spent considerable time in Spain. His earlier publications were mostly in Hungarian--one of the...