Sirius was arrested, accused of murdering Pettigrew and the muggles and of serving Voldemort, and was promptly thrown in prison by Barty Crouch, Sr. without receiving a trial. He spent the next twelve years in Azkaban, brooding over his friends' deaths and obsessing over Pettigrew's betrayal.
This helps us sort answers on the page. 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.
In Prisoner of Azkaban, when Sirius and Remus reunite, the dialogue between them all but admits that Sirius suspected Remus of being the spy. The reason for this is unclear, but we can assume this was feasible, regardless of Remus and Sirius' relationship for a number of reasons: 1.
Lupin Believed Sirius Was Guilty
He believed this throughout Prisoner of Azkaban, only understanding he was innocent when he saw Peter Pettigrew on the Marauder's Map.
The story of Sirius Black and Marlene McKinnon first began in their sixth year at Hogwarts. She was new and he was more than happy to make her feel welcome.
It turns out (naturally) that Sirius was framed, and even after their twelve-year separation he and Lupin remain fiercely devoted to each other. By book 5, the two of them are living together in secret.
Sirius Black
He was then subsequentally burnt out of the family tapestry for daring to be different. Next up: he was imprisoned in Azkaban for over a decade for the murder of 12 Muggles and his former best friend Peter Pettigrew, who actually framed him and faked his own death.
Until the climax of Prisoner of Azkaban, Lupin believed Sirius Black was guilty of murdering 12 Muggles, betraying Lily and James Potter, and killing Peter Pettigrew. He eventually discovered the truth — that Sirius was innocent, and the very much alive Peter was the traitor.
Upon the dais is a stone archway, covered with a tattered black veil. Sirius is hit by Bellatrix's curse, and his stunned body arcs into the air and floats through the archway, disappearing behind the veil.
Sirius Black
"Come on, you can do better than that!"
Dumbledore did know that Sirius was innocent, because he is the one who set up the fidelius charm and the Potters almost chose Sirius, but Sirius thought it would be obvious, so he suggested pettigrew to be the secret keeper.
Alphard Black
Kudos to Alphard for being one figure in Sirius's life who actually supported him.
Sirius didn't exactly improve matters when he tried to sneak into the Gryffindor dormitory by slashing the Fat Lady's portrait. We later discovered that Sirius wasn't a bloodthirsty murderer at all, and simply wanted to get revenge on the real villain of the piece – the not-at-all-dead Peter Pettigrew.
Cruciatus Curse ('Crucio')
Harry tried to use this spell himself. The first time was against Bellatrix after she had killed Sirius.
NeokratosRed used their majorly impressive mathematical skills to calculate that there's a minimum of 50,625 galleons in Harry's vault. Since we know one galleon is equal to around $25, the minimum amount of money in Harry's vault is a mind-blowing $1,265,625!
Tonks believed that he refused to admit his feelings out of nobility. But Lupin was actually in despair, convinced that he could not run the risk of marrying and passing on his lycanthropy to a child. Tonks, convinced that Lupin would never spend time with her again, became desperately unhappy.
This was because werewolf Lupin, conditioned by years of stigma and prejudice, considered himself unworthy of love: that he was somehow too damaged for Tonks to ever return his feelings.
He was afraid of the full moon
The legless spider had vanished. For a second, everyone looked wildly around to see where it was. Then they saw a silvery white orb hanging in the air in front of Lupin, who said 'Riddikulus! ' almost lazily.
Because Sirius is still on the run from wizarding law (having been falsely convicted of killing Peter Pettigrew thirteen years prior), he can't exactly chat with Harry out in the open.
As he was a Black and his entire family had been in Slytherin for generations. Assuming he still hated his family and their beliefs and he, like Harry asked the hat not to place him in Slytherin.
At Hogwarts, she, along with her sisters, was sorted into Slytherin. It is suggested in the novels that, as a student, Bellatrix associated with a group of students – including Rodolphus Lestrange, Severus Snape, Avery, Evan Rosier and Wilkes – who nearly all became Death Eaters.
Sirius Black had a lot of love in his life. Mainly for his best friends but still. One of the greatest loves came not from his connection to James Potter but rather with his relationship to Remus Lupin.
Black did not have a wife or children. As the portrait of Phineas Nigellus, Black's deceased great-great-grandfather, stated, the direct line of the ancient Black family ended with Sirius' death.