Paul Howard was the son of Felisa Howard, the husband of Isabel Howard, and the father of Beverly Howard (later Crusher).
Paul and his wife both died when Beverly was very young, leaving Beverly's grandmother Felisa to care for her. (TNG: "Conundrum", "Sub Rosa")
Paul's name was briefly glimpsed on Beverly's computer bio in "Conundrum". The circumstances surrounding the death of Beverly's parents are vague.