Orochimaru was expelled from Konoha, and while there, he rejected down the position of Hokage. He was adamantly opposed to taking on the duty. Jiraiya even stated that when his parents died, Orochimaru transformed and attempted to study jutsus that would bring his parents back to life. When this failed, he abandoned his studies and traveled the world in order to find a way to revive them. During one of his travels, Orochimaru met with a member of another ninja clan who had found a way to revive their dead by using bloodlines. This clan was called "The Uchiha". The two began working together to create many new vampires. When they were done, Orochimaru brought these vampires back to Konoha where they were given human bodies. The only thing is that these vampires needed feeding on blood to survive so Orochimaru ordered some of his minions to go around killing people for their blood. When this became too easy, Orochimaru decided to make things more interesting by turning some of the humans against their own clans using his favorite technique: Love. This caused many fights to break out between the vampires and their former teammates which led to Konohagakure's decision to expel him. After this incident, Orochimaru left Konoha and hasn't been seen or heard from since. Some sources say that it was because of all of the deaths he caused by creating vampires but this isn't clear cut.