In the 1988 film "Die Hard", what is the name of the terrorist leader?

In the 1988 film "Die Hard", the terrorist leader is Hans Gruber.

Played by Alan Rickman, Gruber leads the armed takeover of Nakatomi Plaza during a Christmas Eve party in Los Angeles. Although he presents his group as politically motivated terrorists, his real objective is a carefully planned theft: opening the building's vault and escaping with approximately $640 million in negotiable bearer bonds.

Gruber is a criminal mastermind from West Germany and the principal antagonist of the film. His intelligence and controlled manner make him a sharp contrast to John McClane, the exhausted New York police officer trapped inside the building. Gruber even disguises himself as an apparently harmless hostage named Bill Clay when he first meets McClane.

Viewers sometimes confuse Hans with Karl, his right-hand man, or Simon Gruber, who appears as the villain's brother in the third Die Hard film. Hans Gruber is also notable in film history because Die Hard was Alan Rickman's first feature-film role. The character's final confrontation with McClane ends when he falls from Nakatomi Plaza.