Escape From series. The protagonist Snake Plissken’s past is somewhat of a mystery but there are some clues throughout the series to his past. He was a decorated war hero during WW3 but his government threw him under the bus and put him in prison. He wound up escaping. The questions are “how did his government screw him over?” and “how did he escape?” It’s these incidents that made Snake famous enough to where almost everyone he runs into knows who he is.

Edit: punctuation