Lily's blood and protection lived on and would last until he came of age. Therefore, if Harry had gone to live with Sirius while he was still underage, he would not be safe from Voldemort.
JK Rowling revealed in an interview (via Mugglenet) that both Harry's paternal and maternal Grandparents had died, leaving Aunt Petunia as Harry's only blood relative. Rowling explains, disposing of Harry's Grandparents was purely to provide a more interesting backstory for Harry.
Sirius Black was born into the House of Black. He quickly began to distance himself from the politics and blood mania of his parents. At the age of sixteen, he ran away from the family home at 12 Grimmauld Place. He went to live with the Potters, and his uncle Alphard Black left him a considerable estate.
Upon looking into Dumbledore's manipulative ways and his intense plans, the most likely reason Dumbledore did not help Sirius is that the result would have interfered with his plans for Harry. Had Sirius not been sent to Azkaban, he would have been Harry's legal guardian instead of the Dursleys.
How did Sirius Black betray Harry Potter's parents?
Peter Pettigrew, the Secret Keeper for the Potter family who betrayed them to Voldemort. Sirius Black was originally meant to be the secret keeper for James and Lily Potter, but Sirius thought Voldemort was on to him (he thought that Remus Lupin was a spy), therefore passing on the Secret Keeper to Peter Pettigrew.
Why Harry Didn't Die in the Forbidden Forest Explained (Canon)
Why did they think Sirius was bad?
Sirius Black is introduced in the third Harry Potter installment as the Prisoner of Azkaban, a dark and menacing figure feared by the Wizarding World almost as much as Voldemort himself. Everyone believes he's a mass murderer who betrayed Harry Potter's parents to the Dark Side.
His help at the Ministry of Magic might result in a smoother mission. Thanks for A2A. No. Sirius had no idea that Harry was a Horcrux, and I think that is one of the kindest things that was done.
No, he didn't know. That's why Rowling specified that in Vold War One the Death Eaters were organised into cells, with each only knowing the identity of a few of the others. So Snape didn't know Pettigrew was a Death Eater, and he didn't know that Sirius wasn't one.
Did the Daily Prophet and Ministry admit that Sirius was innocent after his death? The Ministry absolutely did. Fudge admitted as much to the Muggle Prime Minister. When the latter asked whether Black, the only “DE” he'd been informed of in detail, had joined Voldemort.
As a single werewolf, it is understandable that Remus could not take care of Harry after his parents died. It's also possible he was not informed where Harry was placed and thus couldn't write to him in his early years at the Dursleys.
This idea was incredibly embarrassing to him since Ron vehemently did not want to be cared for by his rich and famous best friend. This is precisely why Harry never tried to give the Weasleys money or give Ron lavish gifts - they didn't want pity.
Several years later, however, Hermione was forced to alter her parents' memories and give them new identities as Wendell and Monica Wilkins, to protect them from the Death Eaters. After the Second Wizarding War ended, Hermione found Mr Granger and his wife in Australia and returned their memories.
With effort, Snape was able to prevent Albus Dumbledore from learning the truth about his loyalties. Due to Snape's facade, Albus Dumbledore trusted Snape for reasons that were kept between them both until Snape murdered him.
Not proven innocent, but after his death, the Ministry did realize that Sirius was in fact innocent, and he was posthumously cleared of all charges. However, in life, Sirius was a wanted man from the moment he escaped Azkaban until the time of his death.
Weasely and Harry, Sirius ends up being innocent. If he had not been, Harry's time at Hogwarts would have been cut agonizingly short. But Molly did not know (and doesn't find out until far later) that Sirius is innocent, and therefore places him in danger by refusing to protect Harry by telling him the truth.
There is always an implicit ire directed at James the most, because as we see in SWM and as Snape's dialogue pretty much everywhere implies, he was the one who lead the bullying. Although he hates Sirius and Lupin quite a bit too.
Did Remus Lupin know Sirius Black was innocent throughout The Prisoner of Azkaban? No. He suspected Sirius until the end of the year, when he spotted Peter on the Marauder's Map.
He hid them using the only thing that would work against Voldemort. He used Fidelius charm and after that even secret keeper was to be protected using that as Sirius said in PoA. The plan failed because wormtail who was their secret keeper betrayed them.
Draco, who implies that he is aware of how Sirius Black was supposedly involved in the deaths of Harry's parents, also taunts Harry about the impending threat of Black: "If it was me, I'd want revenge. I'd hunt him down myself."
Notably, Voldemort appeared to be entirely unaware of this split, as he later created a seventh Horcrux in his quest to have six, and continued to target Harry Potter despite him now holding part of Voldemort's own soul.
Family. Snape's family background is mostly shown in flashbacks during the course of the last three novels. Snape was born to Eileen Prince, a witch, and Tobias Snape, a Muggle, making him a half-blood (hence the name, "Half-Blood Prince").
