Every six months or so, Alan Davis sets out from his seaside bungalow on a far-flung island off the southwestern coast of England carrying a rent check of 12.5 pounds (about $16) for his landlord.
But this is no ordinary landlord, and no ordinary rent check.
Mr. Davis lives on a tiny corner of the Duchy of Cornwall, the property empire controlled by Prince Charles, the heir to Britain’s throne, who has quietly turned an inheritance of rundown farmland into a billion-pound real estate conglomerate. By a quirk of British law, Mr. Davis has to pay the prince for the privilege of living on his land, piddling as the checks may be.
“It’s a feudal way of carrying on,” Mr. Davis said. “They put their finger in and demand money. They’re a law unto themselves.”
Prince Charles’s fortune, long shielded from scrutiny by parliamentary indifference and obscure accounting, spilled into public view this month when his younger son, Prince Harry, announced that he and his wife, Meghan, were quitting their royal duties. In trying to prove that they would renounce taxpayer money, Harry and Meghan gave Britons a peek at the shadowy world of ostensibly private finance that bankrolls the family and its mansions, gardens and considerable staff.
But what the royals call private contains, by any other measure, a generous mix of public giveaways: medieval landholdings passed from one male heir to the next, sweeping tax relief, indemnity from some laws and exemptions from others, ownership of long stretches of coastline and all the treasure buried in Cornwall.
Those perks have delivered Prince Charles substantial wealth. Income from the duchy has nearly tripled in two decades, to £21.6 million, about $28.3 million, last year. But the uproar over Harry and Meghan’s funding has raised uncomfortable questions for the prince and the royals about whether any of their income can truly be considered private.
Coming on the heels of Prince Charles’s brother Andrew being kicked off the royal front lines for socializing with the disgraced financier Jeffrey Epstein, such scrutiny is another dent to the royal mystique.
“Harry has chucked a grenade into the forecourt of Buckingham Palace,” said David McClure, the author of a book about the royal family’s wealth. “It’s weakened the foundations of the royal family and their money, and it’s raised issues that don’t just apply to Harry but have been bubbling under the surface for at least a decade.”
Among the biggest of those is the special treatment afforded Prince Charles’s property empire, an estate that, among other things, pays for the upkeep of his country mansion and furnished £5 million last year for the families of Harry and his older brother, Prince William.
Formed in 1337 to provide the royal heir with an income, the duchy came with fringe benefits: the right to unclaimed shipwrecks on Cornish shores, washed-up whale and sturgeon carcasses, and at least 250 gallons of wine from boats docking at Cornish ports.
Nearly 700 years later, Prince Charles has held onto some anachronistic perks. Into his 20s, the prince is said to have received feudal dues of 100 silver shillings and a pound of peppercorns from the mayor of Launceston in Cornwall.
But with the help of British real estate heavyweights, he has transformed his sleepy holdings into a thriving business covering 200 square miles, turning the focus from rural land to profit-rich urban holdings.
The duchy has a vast footprint, stretching from the rocky shores of Cornwall to south London, and from medieval castles to a granite-walled men’s prison. It recently bought a 400,000-square-foot supermarket warehouse north of London.
A spokeswoman for the duchy said in a statement that Parliament had “confirmed its status as a private estate” and that the Treasury had agreed that its tax status did not confer an unfair advantage. “The prince has always ensured it is run with the interests of its communities as an equal priority,” the statement said.
The duchy’s holdings reflect how the royal family’s wealth has become concentrated in the hands of Prince Charles and his mother, Queen Elizabeth II, whose own estate, the Duchy of Lancaster, paid her £21.7 million last year. Together, the two duchies bankroll more than a dozen members of the family, supplementing a taxpayer grant of £82 million last year reserved for official duties and the upkeep of several palaces.
Despite lawmakers once deeming its current income “an accident of history,” the Duchy of Cornwall has mostly avoided harsh questions, in part by playing up its interest in traditional architecture and sustainable practices across its humbler holdings: scores of farms, much of Dartmoor National Park in Devon and rivers throughout Cornwall. But analysts say that obscures fierce commercial instincts.
