Julius Popper (15 December 1857 - 5 June 1893) was an Romanian-Argentine explorer and engineer best known for his designing of the modern outline of the city of Havana. As an extremely infulential figure, Popper issued his own form of currency, which went into use when the value of the peso collapsed in 1890, and lead the Argentine search for gold during the Tierra del Fuego gold rush.
However, Popper is also remembered as a participant in the Selk'nam Genocide, the genocide of the native Selk'nam in Tierra del Fuego. During the gold expedition in Tierra del Fuego, Popper and his men were attacked by a group of eighty Selk'nam, and violently repelled them with Winchester rifles, killing 78 of them, although two escaped. Popper then had his men take a photograph of him posing with the corpse of a Selk'nam. After this incident, Popper ordered his men to kill all Selk'nam that they found, and hired bounty hunters to hunt them down.
Popper suddenly died in Buenos Aires at the age of 35, and his empire collapsed soon after. His cause of death has never been established, although it is believed that he was poisoned.