Fleet Admiral Kong was the head of the Marines 25 years ago, at the time of the battle of the Edd War, between Gol D. Roger and Shiki. He was seen receiving a report about Shiki fighting Roger, and when Vice Admiral Monkey D. Garp went ahead to the battle, Kong was seen shouting that their conversation was not yet over, despite Garp claiming it is. (Source: One Piece Wikia)