Sebastian Clark was the former leader of the Court of Owls.
In charge of the Court of Owls, Clark was directly responsible for the training of Lincoln March. He then attempted to dethrone the Batman in the Night of Owls, but failed and then failed once again to prevent March's defection. Abandoned by the Court, Clark tried to use Calvin Rose, and later Bane, to take back the Court. In the end, though, he was defeated by Rose, brutalized by the Batman and incarcerated.