Before the advent of Photoshop, being a photmontage artist was a fairly complicated endeavor. For John Heartfield, a German citizen who chose to speak out against the National Socialist Party through his work, it was even more difficult.
Born in 1891 as Helmut Herzfeld he saw the horrors of the First World War first hand. Although propaganda was rife and rabid on both sides he made the extraordinary move of anglicizing his name in 1916, in the middle of the war, to protest against such nationalism.
That, of course, was just the beginning. See more of Heartfield's photmontage series and read the history of his life and work on Kuriositas. Link
Image credit: Smabs Sputzer