Montjoy has a pretty miserable job, as far as being a herald goes, tasked to deliver some pretty arrogant messages from the Dauphin (King Charles VI) as well as from the constable of France to the English king.
Montjoy is an intelligent man, and fully aware of the danger his job puts him in. After all, people aren't exactly lining up to insult a king to his face, so when Montjoy has to deliver insults and harsh threats he does so with wise caution. Instead of simply delivering the message word for word, Montjoy makes a point of separating himself from the French king's message. He does this by quoting the instructions he was given, rather than the message on its own.
"To this, add defiance, and tell him, for conclusion, he hath betrayed his followers, whose condemnation is pronounced." Henry V, Act III, Scene 6.
At times he calls the English king by his nickname, Harry, implying familiarity and perhaps friendship.
These efforts pay off, as not only does King Henry V not punish him for the messages he delivers, but in fact asks his name and even tips him, saying he does his job well.
Ferdinand: An honest prince.
"I might call him A thing divine, for nothing natural I ever saw so noble."
Miranda, on first seeing Ferdinand in The Tempest, Act I, Scene 2
While today's princes might spend their time talking to television chat show hosts (we're looking at you Prince Harry ...) or talking to their plants (ahem, Prince Charles, that would be you), when Ferdinand, Prince of Naples talks, it is focused on his love for Miranda.
Having swum ashore and believing his father, the King of Naples, to be dead, he is enslaved by Miranda's father, Prospero. Falling instantly in love with Miranda (before he has even asked her name), Ferdinand says he will imagine it is her, not her father, who has enslaved him and so the labour will be bearable as he is doing it for her.
Ferdinand is honest, loyal and kind - a perfect match for the equally loving and loyal Miranda. He is a dutiful son, and having promised to marry Miranda while thinking his father has died, on discovering he is alive, immediately tells his father of his duty to Miranda, and seeks his approval.
Ferdinand and Miranda's love story represents purity and innocence in the play, and their characters serve as a contrast to the devious machinations of the generation before them - particularly their fathers.
Ferdinand's love for Miranda also contrasts with the feelings Caliban has for her - while Ferdinand wants to marry her, and make her father his father-in-law, Caliban had far more violent plans for Miranda, seeing her only as a way for him to then populate the entire island with his children. In addition, he had no plans for a relationship with her father, but planned to kill him.
Ferdinand, much like other young princes in Shakespeare's plays, is depicted as being kind, loyal, but with little to say. Presumably Shakespeare never imagined a world where princes indulged in tell-alls to chat show queens.