INFO:

James always made Sirius believe that He could take on the world and treated him like a brother. James then tragically died on halloween 1981. He had the year before gotten a son, and made Sirius The Godfather. Since James wasn’t able to make Harry believe, Sirius had to. He spent 12 years in Azkaban trying to escape, so that he could help Harry, like Harry’s father helped him those many years before.