Queen Elizabeth II wanted the Duke and Duchess of Sussex to continue to have “effective security” after they quit as working royals, court documents have revealed.

The details emerged in the legal judgment given in Harry’s High Court libel case against Associated Newspapers Limited (ANL) on Friday.

The duke is suing ANL over a February 2022 article about his legal challenge against the Home Office following a decision to change his publicly-funded security arrangements when visiting the UK.

An extract from a letter written by the late Queen’s private secretary, Sir Edward Young, to then-cabinet secretary Sir Mark Sedwill on January 31 2020 reported on what had been agreed at the family’s Sandringham summit on January 13.

It outlined the expectations the duke and duchess would have when attending engagements in the UK and the position of his grandmother on these and other issues.

Focusing on security, Sir Edward wrote: “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.

“Given the duke’s public profile by virtue of being born into the royal family, his military service, the duchess’s own independent profile and the well-documented history of targeting of the Sussex family by extremists, it is imperative that the family continues to be provided with effective security.”

And in an apparent nod to the death of Harry’s mother Diana, Princess of Wales, he added: “And, of course, the family is mindful of tragic incidents of the past.”

The judgment stated that the letter did not refer to an offer “personally to reimburse, or proactively to finance, the cost of state security so as not to burden the taxpayer”, which the duke claims he made during the Sandringham summit.

Sir Edward’s letter also went on to make clear the late Queen and the royal family recognised that the process for making decisions about publicly-funded security were “independent” and “are for the UK Government, the Government of Canada and any other host Government…”

High Court judge Mr Justice Nicklin was previously told The Mail on Sunday first reported that the duke was taking legal action against the Home Office in January 2022.

A press statement issued on Harry’s behalf at the time said he and his family were “unable to return to his home” due to the lack of police protection needed in the UK.

It added: “The duke first offered to pay personally for UK police protection for himself and his family in January of 2020 at Sandringham.

“That offer was dismissed. He remains willing to cover the cost of security, as not to impose on the British taxpayer.”