The Duke and Duchess of Sussex's home was renovated with £2.4m of taxpayers' money, royal accounts show.
Frogmore Cottage in Windsor was turned into a single property for Prince Harry and Meghan, from five separate homes.The couple, who moved from Kensington Palace in April before the birth of their son Archie, paid for fittings.
The Queen's Sovereign Grant from the Treasury was £82m in 2018-19, with £33m set aside for maintenance, including major work on Buckingham Palace.
Excluding money transferred to reserves for future building work at the palace, the Queen's official expenses last year were £67m, a 41% year-on-year increase, the figures show.
A large amount of the rise was due to the ongoing renovation at Buckingham Palace, and work on the other occupied royal residences.
Separate accounts show the Royal Family's commercial property arm, the Crown Estate, provided £343.5m to the Treasury in 2018-19, up 4.3% on last year.
The Sovereign Grant is funded by profits from the Crown Estate.Frogmore Cottage sits in the grounds of royal residence Frogmore House, where Prince Harry and Meghan held their wedding reception in May 2018.
The 19th Century property was given to them by the Queen and the renovation paid for out of the Sovereign Grant.
Defective wooden ceiling beams and floor joists were replaced and inefficient heating systems updated. The house also required extensive rewiring - including an electrical sub-station - and the installation of gas and water mains.
The refurbishment took about six months although some areas are yet to be completed, such as repainting the exterior.
The Royal Family's "core" sovereign grant is based on 15% of the net surplus of the Crown Estate, and allocated two years in arrears.
From 2017-18, the total grant was increased to 25% of the surplus for a 10-year period - with the extra funding intended to meet the £369m costs of refurbishing Buckingham Palace.
The royal accounts show the cost of the Prince of Wales and the Duchess of Cornwall's official travel by air and rail funded by the Sovereign Grant rose by almost a third last year to £1.3m, as the couple took on more royal duties from the Queen.
They also reveal the Duke of Edinburgh maintains an office with a private secretary and receives £359,000 annuity from the Treasury. Despite retiring from public duties in 2017, Prince Philip has an official relationship with hundreds of organisations and charities.
Separately, the Prince of Wales pays for the public duties of Prince Harry and Meghan and the Duke and Duchess of Cambridge, and some of their private costs, out of his Duchy of Cornwall income.
Accounts from Clarence House show this funding - in the year Meghan officially joined the Royal Family - stood at just over £5m, up 1.8% on 2017-18.
What is the Crown Estate?
An independent commercial property business and one of the largest property portfolios in the UK
The majority of assets are in London, but the estate also owns property in Scotland, Wales and Northern Ireland
Holdings include Windsor Great Park and Ascot racecourse, but most of the portfolio is made up of residential property, commercial offices, shops, businesses and retail parks