Sirius is the scion of the noble House of Black, they whose motto is Toujours Pur, born to Orion and Walburga Black on March 21, 1959. His birth was followed a year later by that of his younger brother, Regulus. Known dark wizards, the Blacks attempted to raise both boys to believe as they did in the pureblood ideal. But Sirius had other ideas, and resisted their best efforts to indoctrinate him with the racist beliefs they upheld, which led to a growing distance between them. At the age of eleven, Sirius received his acceptance letter to Hogwarts, which was a blessing and a relief to him, his chance to show his parents what he could do, to make them proud. But he was unexpectedly sorted into Gryffindor, rather than Slytherin, the traditional house of the Blacks, to his family's consternation. Things went from bad to worse between them. He tried to avoid going home for holidays, and he never took his friends there, especially Remus, knowing that they would despise him as a halfblood.
However, on the plus side, he met three young boys who became his best friends in the world - and with whom he formed a lasting friendship - James Potter, Remus Lupin, and Peter Pettigrew. They became known as the Marauders, and their pranks became legendary in the annals of Hogwarts. James was the ringleader, but Sirius was his staunch supporter, Remus the naysayer (who ended up being sucked into their shenanigans despite his best efforts to sway them), and Peter, the tagalong, who went along with everything they did, simply in order to belong.
As much as Sirius valued his friends, he took an intense dislike to one of the Slytherin students - Severus Snape - a dislike which was more than returned. He and James went out of their way to bait the boy, including Snape's infamous worst memory when, due mostly to Sirius' boredom, James upended the taciturn young man, to his great mortification, and Lily's disbelief. James and Sirius figured out early in their relationship that their good friend Remus was a lycanthrope, and they saw what a toll his monthly transformations took upon him, so they vowed to do what they could to help, and studying entirely on their own, in greatest secret, they became unregistered animagi, in order to accompany Remus to the Shrieking Shack each month, and help to ameliorate his suffering. It took a few years, and they had to help Peter, because it was very difficult for him to catch on to the complex spells required, but finally, during their fifth year, they succeeded. James' animagus form was a stag, Sirius that of a large black dog, and Peter a rat - which in hindsight says a lot, but they didn't know yet what it meant. Remus was touched at their generosity, and every month the four friends romped beneath the full moon together, and life at Hogwarts went on.
When Sirius turned fifteen, puberty struck with a vengeance, and he began to discover something disturbing about himself - when he looked at Remus Lupin, he found him attractive. Which baffled him to no end. So he threw himself into becoming the Lothario of the school, to figure out his sexuality and try to do something with it. He become the veritable sexgod of Hogwarts - his favourite dating spot being the top of the Astronomy Tower. But sometimes instincts are stronger than we realize, and while he was ogling everything in skirts, it was Remus he felt most comfortable with on a subconscious level, Remus he turned to for advice, for fun, and simply for everything. They confessed their mutual love, at last, during their fifth year, and have been a couple ever since.
At the beginning of their sixth year, Severus pissed Sirius off so greatly, that he did something he should not have done - he lured the boy to the Whomping Willow, where he actually caught a glimpse of Remus in his wolfy state - to his horror. If James had not come along and rescued him, Severus would have died at Remus' unwitting hands. Remus was horrified at what had almost occurred, which brought about a rift between himself and Sirius, the one that brought him to wish himself away from Hogwarts.
Canon point: Right after the infamous Whomping Willow incident, when he almost got Snape killed, and feels as if the whole world is against him and wishes he were somewhere else (OR) Description of AU:
Why did they wish to be somewhere else? Remus won't talk to him, James is mad at him, he didn't mean to let the joke go as far as it did, and he feels completely useless
By the age of sixteen, Sirius has almost reached his full height of five foot ten. He is trim and muscular, a physique acquired through many hours of quidditch play. He has long raven tresses and midnight blue eyes. His hair is the blackest of black, an ebony so deep that sometimes in the right light it acquires blue highlights.His eyes are a deep midnight blue and they seem to possess the ability to pierce one's defenses. Lean and muscular, he has the ability to either walk with an innate dignity or lope like a large dog.
Sirius is a boy at war with himself - and with the world about him, particularly his family. He has never felt completely comfortable with them, and their world, ever since he was old enough to think for himself. His ideas of right and wrong simply didn't conform to theirs, but he held his tongue, because he didn't feel strong enough to argue his position. But the differences between them were only magnified when he entered Hogwarts in 1971, becoming the first Black to be sorted into a house other than Slytherin. (more of this under history). Sirius has a strong sense of honour, and doing what he believes to be right. He also has self-esteem issues stemming from his parents' treatment of him, as well as the things he has seen within his family - e.g. Andromeda being kicked out of the family. He is a staunch supporter of his friends, and would do anything for them. He is also a mischief maker par excellence. And an avid quidditch player - he plays keeper for the Gryffindor team, along with James. And he simply adores muggle things, although he has a lot to learn about them, and loves to listen to Remus talk about various devices and how they are used.
Sirius Black has many layers, most of which are visible only to his closest friends. He is considered by many to be a foolish, vain popinjay, with no ambition and a penchant for pranks and nonsense. He is a practical joker, and enjoys making people laugh, it is true. He can be impulsive, quick to temper, and thoughtless, at times. But he has a very warm and loving heart, and he is loyal to a fault. And he never forgets a slight. He has a laugh that resembles a bark. Sometimes he drinks to excess, and he likes to smoke, but he is aware that it bothers Moony, so tries to refrain when around his friend. He is quite the slob and, used to having house elves both at Grimmauld and at home, he doesn't tend to do well at picking up after himself. As a child, avoiding his parents, though, he spent time in the kitchen at Grimmauld, and by watching the house elves in their duties, became somewhat of a good cook.
His three friends, collectively known as the Marauders, are Sirius' whole life. Especially Remus. For as long as he can remember, he has relied upon Remus for everything - Remus being the sensible one of the lot, and less likely to get in trouble. But it's more than that. Sirius has automatically sought him at every turn, to get his opinion, seek his approval, to simply be with him. His favourite music group is the Doors, and he idolizes Jim Morrison and his hedonistic ways.
Strengths: Sirius is loyal and brave and would do anything for his friends.
Weaknesses: He has a tendency to vanity and to overindulgence, and he does have a temper - a Black trait, whether he wishes to it or not. He has a big ego and also suffers from low self-esteem, thanks to his family. He can be impulsive and doesn't always think things through, which is why he and Remus balance one another out so well. Also, because things come so easily to him, he doesn't always apply himself as he should.
Likes: Remus, quidditch, magic, motorcycles, muggle stuff, eating and drinking Dislikes: rules, his family, bullies, injustice, prejudice,
Skills/powers: He is a rather powerful wizard. When it comes to a fight, he can hold his own, but mostly he uses magic. He is an animagus, taking the form of a large black dog known as Padfoot.
Inventory: his wand, a picture of Remus, journal, a dog collar, clothing, including a Doors T-shirt, his broom
First person sample (must be for the character you're applying for. Not required for second characters but if you feel like writing a sample, go for it!):
Marlene McKinnon caught up with me after Muggle Studies today. I had the feeling she was watchng me, and I was right. She wanted to know if I wanted to go to the Valentine's Ball with her. Merlin! As if I've given that any thought, what with quidditch and all. SIriusly, what is more important, dancing or quidditch? No contest there. But I didn't want to be rude, so I very suavely said that I had not committed myself as of yet. Do I think that will satisfy her? Dunno. At least for now.
Potions is going horribly wrong, and Slughorn has threatened to make me get a tutor if I don't improve. Great. Just what I need. With my current run of luck, I'm bound to get someone truly obnoxious as a tutor - say, Snivellus. Hmmm. Wait a sec. If I screw up the potion and he gets poisoned, that wouldn't be my fault, would it? I'd blame it on bad tutoring. His own fault, don't you know. Now, there is justice of a sort.
Third person sample (may be any character. Not required for second characters, unless you want to provide one.):
Sirius vaulted down the steps which led up to the sixth year boys' dorm and into the Gryffindor Common Room, cannonballing into the room with all of the subtlety of a house afire. "Sirius Black is back!" he announced in an overly loud voice - unnecessarily, as he already had the attention of every occupant of the room, heads turned, eyes following his antics (those that weren't rolling in their sockets). He grinned, pleased at being the center of attention, running a quick hand through his dark tresses as he straddled the chair closest to Remus, nosily looking at the book which was sat upon the lycanthrope's lap.
"Whatcha reading?" he asked, twisting his head as he tried to read the words from his upside down position. "Fun or study?"
"Study. Which you should be doing," Remus pointed out, with raised eyebrows. "Unless, of course, you're finished already. And have the paper written?"
"Paper?" Sirius paled, his mouth falling open in a gasp. "Merlin, we have a paper due? What subject?" WIthout ceremony, he turned the book about toward him, earning an irritated scowl and a glare from Remus. "Oh damn!" the animagus swore violently. "I HATE History of Magic! Why didn't you tell me we had a paper to write, Rem?"
"Not my place," Remus reclaimed his book, shaking his head, but not unkindly. "SIrius, honestly, I'm not your mother. Or your nursemaid." He sighed at the look on the stricken boy's face, relenting, of course. "Come on, start reading, I'll help you get finished on time." And was rewarded with a big Sirius smile.