After the wedding, when news came out about which Champagne the glamour couple were toasted with, sales in Japan went crazy.
"Japanese couples wanted to get married with Pol Roger, no doubt because of the Royals," says D'Harcourt.
But Pol Roger is not resting on that fame and reputation. "These days we only use the first and best pressing for all our wines ... we are striving to be more precise."
And high prices for French Champagne are likely to continue, he adds. "A kilo of grapes in Champagne is very expensive, as is the price of land - one hectare is now more than a million euro."
Despite the high price tag, the world still hankers after French Champagne. After World War II 30 million bottles were produced - last year it was 330 million.
Someone other than royalty and statesmen must be buying it.
RECOMMENDED
Pol Roger Brut Reserve NV, $89
Entry level, this is one-third pinot noir, one-third chardonnay and one-third pinot meunier, thereby covering the traditional Champagne varietals. It is delicate and gentle, with hints of fresh apple, cut flowers and spicy vanilla.
Pol Roger Blanc De Blancs 2000 Grand Cru, $140
100 per cent chardonnay, this is known affectionately by Pol Roger as "our liquid diamond". It has a lovely dry finish with flavours of melon, fresh fruit and a flinty mineral freshness.