Bogard is a Marine Headquarters Marine and the right hand man of Vice Admiral Monkey D. Garp. He was instrumental in training Koby and Helmeppo. He seems to be very good at using a sword, as he was able to cut up Koby’s guns without hurting him and later was training them using only one hand to defend himself.
He is most recently seen with Vice Admiral Garp in Water 7.
He is based off of the actor Humphrey Bogart, most notably in Casablanca in terms of appearance and name.

(Source: One Piece Wiki)