Captain Joses la Sonrisa looks at you blankly when asked about his past, as if it was none of your business and you should only worry that he's in front of you right now. He grabs his drink and drinks abundantly from it, almost finishing it. "It's not your business who I was. I'm here right now and that's what matters". He looks away and orders another drink to the innkeeper before finishing the one in his hand.

From what you were told by the man that put you both in contact, he was part of of the personal guard from a lord in the north that had a reputation of not fearing conflicts with the surrounding estates. Probably there is where Joses learned to fight and where he got that ugly scar in his face that turned his smile into something awkward.

Then one day he was working for that lord, and the next day he wasn't. He left the area to start working as a hired sword, but it is difficult to find nothing more than tavern stories about what really happened back then.

You've also know that despite being called Captain by most of his former colleagues and acquaintances he never got that rank and that he being called Captain has to do with a story that happened a few years ago in a skirmish with another lord's guard.

Unfortunately to know the details of that story you'd need to ask Joses directly, as everyone else in that story is now dead.