The Vampire Council, also known as the Council of Elders or The Senate, was tasked with protecting the last remaining Pureblood families.
The Council of Elders controlled the Vampire society. They were given control by the last Kuran King (Rido, Haruka and Juri Kuran's father) when he yielded his kingship. The Ichijo and Shiki families are known to be Pro-Council. The last Head of the Council was Asato Ichijo.
Before Yuki was awakened to her Pureblood state, the Hunter's Association and the Vampire Council conspired together–or rather their leaders Asato Ichijo and the Hunter's Association President–with the intention of following the mad king Rido Kuran and gaining more power. Asato Ichijo's motive was to replace Kaname Kuran with Rido Kuran, making him Head of the Kuran family. This would also make the Council have more control. In return for the Hunter's Association's help, Asato gave the President Rido Kuran's powerful Pureblood blood, unfortunately turning him into a vampire.
The Council was destroyed by Kaname Kuran, as being unable to distinguish between right and wrong, when he killed the highest members of the Council. However, since the destruction of the Council, the former lower ranked members, young vampires have now been causing trouble going wild in the neighborhoods..If a Pureblood was killed, they would have their murderer killed.
In Vampire Knight Guilty, Zero was accused of being the murderer of Shizuka Hio. When in truth, it was Kaname. Yuki has a small mysterious conversation with a vampire outside the school, and the vampire attacks her. Yuki is then saved by Zero, and Zero kills the vampire using the Bloody Rose. More vampires approach Yuki and Zero. Just before they can attack, Kaname and the Night Class arrive and turns them to ash and Kaname injures one of the henchmen's shoulder. The remaining men tell Kaname that his desire to protect a murderer, will be reported back to the Senate.