Hagrid tells Madame Maxime that his father was broken-hearted when his giantess mother left them. His father was a tiny man, short enough that by the time Hagrid was six years old, he could lift his father up and put him on top of the dresser.
Mr Hagrid was thrilled when his son got into Hogwarts, having thought Rubeus might not be a wizard because of his giant blood. He died when Rubeus was in his second year at Hogwarts. He was proud of his son, and always told him that he should never be ashamed of himself.