The substantial amount spent on this legal battle may lead to questions regarding the appropriateness of a member of the Royal family challenging the government through legal means.
Data from a Freedom of Information request reveals that the total expenditure for defending against two separate judicial review claims brought by the Duke of Sussex regarding his security matters totaled £514,128.
This cost covered expenses such as over £180,000 for counsel, about £320,000 for the Government Legal Department, around £2,300 for court fees, and nearly £10,000 for e-disclosure.
In February, after an extensive legal process lasting two-and-a-half years, Mr Justice Lane delivered a scathing 52-page ruling rejecting the Duke's case.
The judge found that the decision from the Royal and VIP Executive Committee (Ravec) to revoke state-funded security for Prince Harry and Meghan when they stepped back as working royals and to review it on a case-by-case basis upon their return to the UK was not unreasonable or procedurally unfair.
He also dismissed the Duke's interpretation of the process as "inappropriate" and emphasized that taxpayer-funded security should not be used to shield the couple from paparazzi.
Following this ruling, Prince Harry was left facing a projected legal bill exceeding £1 million.
Despite this setback, he has declared plans to appeal the decision, suggesting that the costs could escalate further.
Prince Harry maintains that being stripped of guaranteed police protection makes him vulnerable during visits to the UK, and he must provide a 30-day notice for his travel plans to be assessed.
Sources close to him assert that he is unwilling to return to the UK with Meghan and their children without the security level he deems necessary.
When informed of the removal of his taxpayer-funded police protection in early 2020, the Duke expressed anger and demanded to know the individuals responsible for this decision.
In an email sent to Sir Mark Sedwill, the then Cabinet secretary, he insisted on being informed of who had exposed him to such vulnerability.
In September 2021, shortly after a visit to the UK involving engagements alongside his brother Prince William, the Duke filed for a judicial review.
This challenge was based on alleged lack of transparency regarding Ravec's structure and processes, contending he had not received a clear explanation about the committee's composition and functioning.
Additionally, Prince Harry argued that he had been treated unfairly and subjected to unlawful treatment compared to others by Ravec.
Aside from his legal tussles with the government, Prince Harry is also pursuing legal actions against News Group Newspapers and Associated Newspapers.
Earlier this year, he faced an estimated legal bill of £750,000 after dropping a libel lawsuit against the Mail on Sunday concerning an article on his request for taxpayer-funded security.
In a separate case, he accepted "substantial" damages to conclude a four-year legal battle with Mirror Group Newspapers instead of proceeding with a second phone hacking trial.