 Complete the following phrase:  He returned to London and became a pupil under A. B. Clay, but was back in Germany a few years later, this time studying at the Düsseldorf school of painting in Europe, where he studied under the German military artist, Emil Hünten, himself an ex-pupil of Horace Vernet, and at the time military and historical painter to the Prussian emperor. Under Hünten, Crofts talent as a military painter grew, and in 1874, he exhibited Retreat, representing an episode in the Franco-Prussian War during the Battle of Gravelotte, and in the same year, another scene from the same conflict, One touch of nature makes the whole world kin which won him the Crystal Palace prize medal. Both scenes were influenced by the artists experience of witnessing some of the closing stages of the war, especially the battles of Weissenbourg, 