Colonel Nicholas Joseph Fury Sr. is a fictional character appearing in American comic books published by Marvel Comics. Created by writer/artist Jack Kirby and writer Stan Lee, he first appeared in Sgt. Fury and his Howling Commandos #1 (May 1963), a World War II combat series that portrayed the cigar-chomping man as leader of an elite U.S. Army unit.
The modern-day character, initially a CIA agent, debuted a few months later in Fantastic Four #21 (Dec. 1963). In Strange Tales #135 (Aug. 1965), the character was transformed into a spy like James Bond and leading agent of the fictional espionage agency S.H.I.E.L.D. The character makes frequent appearances in Marvel books as the former head of S.H.I.E.L.D. and as an intermediary between the U.S. government or the United Nations and various superheroes. It is eventually revealed that he takes a special medication called the Infinity Formula that halted his aging and allows him to be active despite being nearly a century old.
Source: Wikipedia, "[en.wikipedia.org/wiki/Nick_Fury Nick Fury]", available under the CC-BY-SA License.