Leonidas I

King Leonidas was a Spartan King who was famous for leading an army of 300 Spartans in a battle against impossible odds, during which he was killed

In the Parodies
IIn the Downfall Parodies, Leonidas is usually portrayed using clips from the popular movie 300, particularily his famous line "THIS IS SPARTA!".

For reasons unexplained, Leonidas seems to be convinced that Berlin is in fact the city of Sparta, and has on a number of occasions attempted to convince Adolf Hitler that this is the case, resulting in a heated argument when Hitler attempts to explain that it is Berlin.