Admiral Edward Jellico originally appeared in the TNG episodes "Chain of Command Parts 1 and 2" (as played by Ronny Cox), at which time he held the rank of Captain. As the New Frontier series began, Jellico was the admiral serving over Sector 221-G. He had a rather hostile relationship with Calhoun, although this relationship has softened over the years.
Read more about this topic: List Of Star Trek: New Frontier Characters