The Loser Janitor is the Ultimate Legend

Thirty years ago Cyril, a grand duke, put an end to an alien invasion. His wife died in the course of it. He gave up the rank and the money that came to him for it and dropped out of sight, took work as a janitor, and brought up his son on that. Long after, he saves a girl. The girl's mother is a tycoon, and the rescue leads to the two of them being set up together. The people around the mother take him for what his job says he is and say so where he can hear it. He lets that stand for a while. Then he tells them what he was, and the ones who had been loudest about it back off. The aliens come back a second time. The corporations sit down to work out whether saving the poor is worth doing.