During his later years, as for instance in the "Bible series", subjects were more dramatic. He managed to blend the real with the fantastic, and combined with his use of color the pictures were always at least acceptable if not powerful. He never attempted to present pure reality but always created his atmospheres through fantasy. In all cases Chagall's "most persistent subject is life itself, in its simplicity or its hidden complexity... He presents for our study places, people, and objects from his own life". After absorbing the techniques of Fauvism and Cubism (under the influence of Jean Metzinger and Albert Gleizes) Chagall was able to blend these stylistic tendencies with his own folkish style. He gave the grim life of Hasidic Jews the "romantic overtones of a charmed world", notes Goodman. It was by combining the aspects of Modernism with his "unique artistic language", that he was able to catch the attention of critics and collectors throughout Europe. Generally, it was his boyhood of living in a Belarusian provincial town that gave him a continual source of imaginative stimuli. Chagall would become one of many Jewish émigrés who later became noted artists, all of them similarly having once been part of "Russia's most numerous and creative minorities", notes Goodman. World War I, which ended in 1918, had displaced nearly a million Jews and destroyed what remained of the provincial shtetl culture that had defined life for most Eastern European Jews for centuries. Goodman notes, "The fading of traditional Jewish society left artists like Chagall with powerful memories that could no longer be fed by a tangible reality. Instead, that culture became an emotional and intellectual source that existed solely in memory and the imagination... So rich had the experience been, it sustained him for the rest of his life." Sweeney adds that "if you ask Chagall to explain his paintings, he would reply, 'I don't understand them at all. They are not literature. They are only pictorial arrangements of images that obsess me..." In 1948, after returning to France from the U.S. after the war, he saw for himself the destruction that the war had brought to Europe and the Jewish populations. In 1951, as part of a memorial book dedicated to eighty-four Jewish artists who were killed by the Nazis in France, he wrote a poem entitled "For the Slaughtered Artists: 1950", which inspired paintings such as the "Song of David" (see photo):  Lewis writes that Chagall "remains the most important visual artist to have borne witness to the world of East European Jewry... and inadvertently became the public witness of a now vanished civilization."