The fire at Windsor Castle destroyed the Great Hall and St Georges Chapel
The Royal Family has tacitly backed campaigners fighting the partial closure of Windsor Fire Station, the local Fire Brigades Union head claims.
Michael Rowley said letters sent to him on behalf of the Royal Family from 2006 to 2008, including one from the Queen, show a "guarded backing".
The fire authority plans to withdraw night-time service at Windsor - providing cover from Slough instead.
Windsor crews helped to tackle the Windsor Castle fire in 1992.
The Windsor Castle Fire Brigade, based at the castle, were first to the scene but crews from Windsor also attended along with more than 200 firemen from the rest of Berkshire, London, Buckinghamshire, Surrey, and Oxfordshire.
The fire started in the private royal chapel and severely damaged the north-east section of the castle, including St George's Hall and the Grand Reception Room.
The Royal Family avoid becoming involved in political battles but Mr Rowley said: "If they send us their best wishes and good luck, it's very telling in itself".
Local celebrities including Sir Elton John, Rolf Harris, Sir Alan Sugar and singer Natalie Imbruglia are among a list of well-known names who have also backed the campaign for Windsor fire station to stay open overnight.
Mr Rowley added: "There's never been a fire station campaign like this in the UK before - to have unprecedented royal support and celebrity support."
A senior correspondent at Buckingham Palace said in a letter dated 12 May 2006: "Her majesty understands your reasons for writing as you did, and has taken careful note of your concerns."
In a letter dated 10 July 2007, the Duke of Edinburgh explained he could not help "directly" but sent his "best wishes for the future".
The letter, sent by an equerry, adds: "His Royal Highness has suggested that you write to the local authority in Windsor in an effort to put a halt to the proposed closure of the fire station".
'Best of luck'
The Duke of York, who helped the effort to rescue many art treasures during the 1992 fire, offers his "sympathy" in a letter from a private secretary on his behalf on 5 October 2007.
"While his Royal Highness has great sympathy with your aims to retain 24 hour cover in Windsor in 2008, as a member of the Royal family he is not in a position to provide public support for your campaign," it stated.
"However, the Duke of York has asked me to send his best wishes and best of luck with your campaign."
The Princess Royal, in a letter sent by a private secretary on her behalf, dated 23 June 2008, said: "Her Royal Highness congratulates you on your work as a firefighter in Windsor and sends you and your colleagues her best wishes for the future."
The Royal Borough of Windsor and Maidenhead Council is seeking a judicial review of the plans to withdraw night-time cover.
The case will be heard at the High Court in London on 17 February.
Berkshire Fire Authority said the closure plan was "part of a county-wide programme to improve levels of fire cover where it is most needed".