I wrote Lucas Brown's story because I thought he was getting a raw deal--every mention I saw of him dismissed him as a useless drunk who was taking advantage of poor Will and his obviously-superior blacksmithing skills (when he wasn't horrifically abusing Will-the-boy, that is) without any of them stopping to think that Will had to learn those superior skills from *somebody*, and Brown was the most likely suspect.

As for Mr Stevens--whose total canon reference is literally a line shouted by Norrington in the heat of the Battle of Port Royal--I originally used his name for a bit character in a Sparrington story (Dreams & Desire) on a whim, and then when it looked like he'd get a bigger part in the sequel Stevens suddenly started demanding a backstory all his own, and it sort of took off from there.

AFAIK those are the only two minor canon characters I ever gave center stage to--and Stevens is never really center stage, as his backstory is told from Gillette's POV. I don't count Gillette & Groves as they were pretty fully developed fandom-canon characters before I came onto the scene.