Boris III Of Bulgaria [Getty Images]

Boris III, Tsar of Bulgaria (1894 - 1943), circa 1930. (Photo by Paul Popper/Popperfoto via Getty Images/Getty Images) — see more

Boris III, Tsar of Bulgaria (1894 - 1943), circa 1930. (Photo by Paul Popper/Popperfoto via Getty Images/Getty Images)

Popperfoto Paul Popper/Popperfoto