Karl Stromburg was a rich, reclusive marine biologist and would-be genocidal madman.
As a child he had always been quick to anger, and kept a pet piranha fish to which he fed frogs. This worried his parents, who operated a funeral home for a living. Stromburg, as a young man, had killed his parents by sabotaging their car to cause it to crash, and he took over their funeral home business. Instead of cremating bodies he would steal jewelry and cold teeth from the deceased, and this, combined with the money given to him by the deceased's grieving relatives, allowed him to both attend school to become a marine biologist as well as found his own shipping company.
With the help of Dr. Bechmann and Professor Markovitz, Stromburg developed a method of tracking submarines. He planned to use this method to capture subs and loot their arsenals of nuclear weapons, with which he then planned to destroy the world. Unfortunately, his secretary Kate Chapman betrayed him and sold the film on the black market, and thus Stromburg sent his two toughest assassins, Jaws and Sandor, to retrieve it. In the end, he was shot by James Bond aboard his submarine base, Atlantis.
In Christopher Wood's novelization of The Spy Who Loved Me, Stromburg's first name is actually given as Sigmund.