Nobody knows who these guys are. Evidence suggests they don’t know each other very well either. Apparently they met in a tavern and, based on five minutes of small talk and the flimsiest of pretexts, decided to band together in greedy quest of sanctimonious glory, gold, and magic items.
These adventurers seem to think that they're the center of the universe. They fearlessly throw themselves at monsters which make most sane people quake in their boots, but agonize over dumb things like who's going to open the door first, and whether to drink the wine at a party. They tend to be overdramatic, especially that wizard there in the back row, and the fighter looks as if he's posing for a painting or something whenever the light shines through the leaves just so. For some reason half of them have British accents of one sort or another, though not all the time. Despite their general incompetence at basic woodcraft and traveling skills, the Adventuring Band has shown an alarming facility for eking out victories against nearly every foe, whether great or small.
There’s probably a backstory of some kind or other for each of these characters, but frankly we don’t care.