Ethan Hunt is an agent with the Impossible Mission Force.
In his early 30's as the series begins, he moves from being the right-hand man and go-to guy for the team leader to being a team leader himself as the series progresses. His role changes for a time to near retirement as he becomes an instructor to going back to the field when the situation gets crazy enough to demand id.
A product of a solid mid-Western farm upbringing, Hunt loved challenges and pushing himself harder than any employer would imagine. After college, he joined the military and moved immediately for membership with the Special Forces. After his tour of duty was ended, he was recruited by the CIA to be a field operative and did that for a handful of years before growing very disillusioned by the petty bickering and bureaucracy of the Agency.
He knew he was going to leave but the question remained where to and that was answered with Jim Phelps, current leader of the highly secretive IMF and one of the co-founders of that department, courted him and wooed him into the fold. For the next half decade he moved up the ranks at the IMF and proved over and again how resourceful and capable he was. And his friendship and loyalty to Phelps grew along with it, even when Phelps reluctantly allowed the IMF to be swallowed up by the very Agency that Hunt had grown tired of. As long as Phelps was buffer in between, Hunt was content.
In the IMF, Hunt's role was that of the infiltration man. An incredible gift with languages, paired with an almost uncanny mimicry ability, made Hunt a perfect agent to assume roles that got him into places he was not meant to be. Adding in the lastest of facial masking and voice alteration, he could become just about anyone. When, as it sometimes did, a plan went wrong, his physical prowess and quick thinking kep him alive.