The Prince of Wales' pre-tax income rose by nearly a fifth last year to nearly £12m, a royal report has shown.
The report focuses on Charles' public role
The Duchy of Cornwall, which provides Prince Charles' annual income, grew in value by £55m last year - thanks in part to the healthy property market.
Clarence House's first annual review of his work and accounts showed his income was used to meet some personal costs for Camilla Parker Bowles.
The prince also helped to raise around £100m for charity in the year 2003-04.
He met an estimated 10,000 people during his 517 engagements and hosted 9,000 guests at royal residences.
The prince received around 33,000 letters from the public and wrote 2,000 himself, with a further 10,000 written on his behalf.
According to the review, his pre-tax income grew by nearly £2 million to £11.9 million in 2003-04, with the value of his estate increasing by 14%.
The prince's income puts him among the UK's top earners, a London-based financial expert said.
Justin Urquhart Stewart, of Seven Investment Management, said Charles would be "in the top 100 in terms of income".
But he added that "there's not a lot he can do" with his wealth, given that he is not allowed to make money from the sale of the duchy's properties.
The prince's private secretary, Sir Michael Peat, said: "People are entitled to know how the Prince of Wales fulfils his public role."
Sir Michael Peat played down the references to Mrs Parker Bowles
The report marked the first time that Mrs Parker Bowles had been mentioned in the prince's accounts, with three references to her appearing in the 48-page document.
Sir Michael said her appearance in the review was "not hugely significant".
"Obviously her staff have an office to cope with work that arises because of her connection with the Prince of Wales."
The number of full-time staff employed by the prince increased from 91 to 112, including 73 by the duchy, which spans around 56,000 hectares and is worth more than £463 million.
Created in 1337 by Edward III, the duchy's main purpose has been to provide an income for the heir to the throne.
Prince Charles, who is the 24th Duke of Cornwall, does not own the duchy's assets but is entitled to its annual net surplus.
Properties from which he receives an income include The Oval cricket ground and Dartmoor Prison.
Grants-in-aid to the prince, for official travel and the maintenance of royal residences, also increased, from £2.7 million to £3.8 million.
The prince voluntarily pays income tax at 40% on his duchy income and, like William and Harry, does not have an allowance from the Civil List.
Charles' tax bill was included in his £4.4 million personal expenditure, and he spent a further £5.9 million on official duties and charitable activities, the figures revealed.
The review divided Charles' duties into three areas: supporting the Queen, working as a charitable entrepreneur and promoting Britain.
It sums up by saying that he seeks "to use his unique position to make a difference for the better".
The BBC's Royal Correspondent Peter Hunt said the prince's aides had stressed the review's "emphasis on accountability".
He added that they were "very keen to focus on the work that he does and not his private life".