And in marketing terms, her status as a “top-notch corporate heritage brand can directly or informally endorse not only products, services and corporations but also places that may confer distinctiveness and prestige.”

“Traditionally the aristocracy and the wealthy wished to be near the center of royal power,” he said, so an area like St. James’s in London still has some of the most fashionable shops and residences in the city.

A 2015 survey found that 43 percent of Londoners would consider paying more for a property just because it had a regal-sounding street name, like Royal Drive, King Place or Queen Crescent, even if there were no genuine royal connection to the property.

Susie Hollands, the founder of the French-based agency Vingt Paris, has no doubt why there has been sharp international interest in an 18th-century home south of Versailles that she is marketing.

The 26-acre Moulin de la Tuilerie was bought by Wallis Simpson in 1952 as a country retreat for herself and her husband, the former King Edward VIII, until his death two decades later. (The two were known as the Duke and Duchess of Windsor after King Edward abdicated in 1936 to marry Ms. Simpson.)

“Buyers are pretty savvy and will not pay a fortune just for a sort of celebrity hysteria, but there is certainly a lot more interest in this property because of the romance of its history with the Windsors,” Ms. Hollands said.