Throughout Picnic at Hanging Rock, the narrator repeatedly emphasizes Mike's English identity, which develops a disconnect between the character and his Australian surroundings. Through a historical allusion at the end of Chapter 7, Lindsay reinforces—and makes fun of—Mike's English ancestry.

As Mike clambers up Hanging Rock at the end of Chapter 7, both his physical and mental state gradually disintegrate. In order to keep going, he recalls the strength and persistence of his ancestors in the Hundred Years' War. Through this historical allusion, Lindsay gives the reader insight into the character's background and how he sees himself.

A spear of pain jabbed at his ankle, he got up again and started hauling himself up on to the next boulder. There was only one conscious thought in his head: Go on. A Fitzhubert ancestor hacking his way through bloody barricades at Agincourt had felt much the same way; and had, in fact, incorporated those very words, in Latin, in the family crest: Go on. Mike, some five centuries later, went on climbing.

The Battle of Agincourt, fought in 1415, was an important battle in the Hundred Years' War. Although the English were significantly outnumbered in the battle, they defeated the French force. By alluding to this historical event, Lindsay suggests that Mike is in the midst of his own personal Agincourt.

Part of what makes this allusion interesting is the disconnect between the tone of the narration and the mood of the scene. While Mike is in great pain and the moment feels intense and grim, the delivery of the allusion feels humorous. By comparing Mike's climb up Rock to the Battle of Agincourt, and going in detail about the family crest, the narrator seems to be making fun of the Fitzhuberts and their sense of historical self-importance. One can argue that this imbalance is typical of the book overall: while there's something dismal and forbidding about the setting, events, and characters, the narration consistently remains lighthearted and at times even wry.

The allusion can also be connected to a postcolonial critique. Earlier in the novel, Mike reminds himself that he's "in Australia now: Australia, where anything might happen. In England everything had been done before: quite often by one’s own ancestors, over and over again." While England, for Mike, is a place of historical continuity in which his roots extend back for several centuries, Australia is brand new. In this way, Mike represents the British colonizer, who sees Australia as a blank slate and neglects to acknowledge the far-reaching history and culture of the native Aboriginals. When Mike recalls the Battle of Agincourt and his family crest on Hanging Rock, Lindsay creates a sort of vignette that encapsulates the British colonization of Australia. Ultimately, the allusion to 15th-century European history feels immensely out of place in the Australian bush.