[He finds himself just looking at Hermione before answering her question.]

Gladiolus' family, the Amicitias, have served the kings of Lucis for several generations. Gladio is Noctis' shield as much as I am his tactician. We both grew up and trained in the palace for our positions in the Crownsguard. Prompto, on the other hand, came from a rather normal family and met Noctis in school, where they became friends.

Sadly, one doesn't merely befriend the crown prince. After graduation, Prompto went through some training and joined the Crownsguard too.