The figure was one insight into the heir to the throne's world offered in an annual review of his finances and activities yesterday which showed that his income from the Duchy of Cornwall Estate had risen by 11 per cent to more than £13m. In addition, the Prince of Wales received 4p in grants from each taxpayer.
Details emerged as the 56-year-old Prince presented The Ashden Awards for Sustainable Energy at Clarence House while his wife opened a shop on the Duke of Wellington's estate.
The 52-page report – printed in Gaelic for the first time at the Prince's request – revealed that 23,083 people put pen to paper after the couple announced their engagement. Of these letters, 22,010 were supportive but 1,073 were not.
"All the letters were passed to them and all, except the very abusive ones, were replied to," explained his private secretary, Sir Michael Peat, yesterday.
The report – which features a wedding picture of the Prince and his bride on the cover – revealed that Charles, Camilla and his sons William and Harry received in government grants seven per cent of the 61p per person given to the monarchy.
Charles's private income rose by 11 per cent during the year. The Duchy of Cornwall – the 54,850 hectare estate established in 1337 by Edward III to provide for his eldest son, the Black Prince – gave him £13,274,000 compared with £11,913,000 in 2003-04. The increase was said to be because of rising income from commercial properties, while agricultural rents fell.
Nevertheless the Prince received further government grants of £2,688,000 for official travel, communications and property maintenance.
For the first time, the Prince's travel bill exceeded more than £1m. He travelled more than 65,700 miles to official engagements, approximately two thirds abroad – costing £1.06m, compared with £825,000 in the previous year.
He visited 82 towns, across 35 counties, but also attended 103 official engagements in Italy, Turkey, Jordan, Sri Lanka, Australia, New Zealand, Fiji, Spain, France, the United States, Bosnia, UAE, Germany and the Netherlands.
The Prince was recently criticised for his round-the-world tour in February, which cost £292,000 of the Royal Family's £5m annual travel budget.
Obviously conscious of potential reproach, yesterday's annual review said: "It is an important part of the Prince of Wales's role as heir to the throne to bring together people in different parts of the UK, to act as a focal point for national life and to represent the country overseas.
"This involves a significant amount of travel that needs to be undertaken in a way which meets efficiency, security and presentational requirements."
The report explained that the Prince undertook more than 500 engagements and entertained 7,400 official guests last year. He attended 191 formal meetings and received more than 47,000 letters from the public.
Influenced by his grandmother, the late Queen Mother, the Prince is said to be a keen letter-writer and the review said he personally penned more than 2,300, while a further 18,000 were written on his behalf.
The Prince has founded 16 core and two funding charities and the report stated that he raised £109m for them while donating £2.5m of his own money.
Duchy Originals, his increasingly successful organic foods company, made a £1m profit for the second consecutive year, on retail sales of almost £40m, with all profits given to charity.
The last financial year's tax – which he pays at normal rates, chiefly 40 per cent – and personal expenditure amounted to £5.2m compared with £4.4m the previous year.
His personal staff – which includes two butlers, a valet, four chefs, two chauffeurs, eight housekeepers and eight gardeners as well as a secretary, and one full-time and two part-time assistant secretaries – cost £3.8m, including £96,000 on housekeeping.
* Miles travelled: 65,700
* Cost of travel: £1.06 m
* UK towns visited: 82
* UK counties visited: 35
* Countries visited: 14
* Income from Duchy of Cornwall: £13,274,000
* Government grants: £2,688,000
* Cost to taxpayer: 4p a year
* Amount raised for charity: £109m
* Personal donations to charity: £2.5m
* Engagements attended: more than 500
* Engagements abroad: 103
* Guests entertained: 7,400
* Meetings attended: 191
* Letters received: 47,000
* Letters personally written: 2,300
* Letters written on his behalf : 18,000
* Duchy Originals sales: £40m
* Duchy Originals profit: £1m
* Staff costs: £3.8m
* Housekeeping costs: £96,000
* Gardening costs: £30,000