Dr. Helmut Caligari was a German mesmerist, who carried out a series of murders using a somnambulist assassin named Cesare.
Caligari, along with Dr. Mabuse, was one of the leading minds and most influential forces in Die Zwielichthelden, the German version of the League.
Following the death of Carl Rotwang, another member of Die Zwielichthelden and the creator of the Berlin Metropolis, Caligari governed the city with the help of Maria and his Sleep-Commandos.
Caligari was killed by Janni Dakkar in a confrontation in the Berlin Metropolis in 1941. At this time, due to extreme old age and ailing health, he uses a powered wheelchair and a respirator mask.