A troubled young Terran, Gröner attempted to join the Imperial Army but was turned down due to a history of mental illness.  Undaunted, he began a short-lived career as a political candidate best known for his inflammatory xenophobic rhetoric.  Gröner was unable to garner votes for office, and the beginning of the Sunrise War transformed him into a fanatic.  Pamphlets published at his own expense advocated total war against the Southern Alliance and the unconditional surrender of Gatraxia. 

Politically marginalized by public sentiment to win and end the war quickly, Gröner began to plot against figures associated with the peace movement.  Following the announcement that Emperor Ivan Romanov also favored a speedy end to the war, Gröner decided to strike during the Emperor's next planned speech.  One 28 August 2242, during a speech that was to announce a future policy of armed neutrality, Gröner drew his weapon and assassinated  Romanov.  Though quickly apprehended by the Imperial Guard, Gröner proved difficult to handle, and managed to hang himself in his cell.