Don't story-splain your character's backstory like this is the first moment they've ever thought about their life. The trick is to write it like a friend telling you some gossip. Gossip has a voice, a point of view, and is juicy. We want to know more.
"The thing about the West End Guards, they were easily bribed until that thing with Harlow went down."
You don't need to explain what happened with Harlow yet — that's the seed you've planted for later — but the reader knows the Guards can't be bribed easily anymore.
Backstory earns its place when the reader flips the page to find out what happened, not when they feel informed.