The late Queen's sentiments came to light amid Prince Harry's ongoing dispute with the Home Office, which revoked his security following his and Meghan Markle's decision to step down as working royals in 2020.
The Telegraph reported on letters exchanged between the former monarch's private secretary, Sir Edward Young, and the then-cabinet secretary, Sir Mark Sedwill, presented in a UK court.
The excerpt from the letter highlighted the late Queen's instructions regarding her grandson's security, stating, "You will understand well that ensuring that the Duke and Duchess of Sussex remain safe is of paramount importance to Her Majesty and her family."
Considering Prince Harry's public profile, military service, Meghan Markle's independent profile, and the well-documented history of targeting the Sussex family by extremists, the letter emphasized the imperative need for effective security.
The late monarch underscored that this decision was made in consideration of the "tragic incidents of the past," likely referencing the unfortunate events involving Princess Diana, Prince Harry's mother.