The episode won an Emmy Award for Outstanding Directing for a Drama Series.
"Paterfamilias" is Latin for "the male head of a household." The title of the episode may refer to Charles' learning to stand up for himself to prepare for manhood as the heir apparent or to Philip's asserting his authority over the children's education in spite of Elizabeth's wishes, but most likely both.
This episode represents a small chronological backtrack for the series, as the previous episode ended with the Kennedy assassination (November 1963). Charles started attending Gordonstoun prior to that, in April 1962.
The sign hanging across the road as Philip follows his sisters casket reads: The German student sings for Führer and People.