The product line at Rome's Annibale Gammarelli shop, tailor to the popes and lesser men of the cloth, has remained more or less unchanged for centuries. Prada it is not.

The clients come to shop for buskins (silk boots) and palliums (circular bands with hanging pennants); cassocks (full-length garments) and chasubles (sleeveless outer vestments); birettas (box-like caps) and zucchettos (skull caps).

"The fashion has not changed at all," says Lorenzo Gammarelli, 40, a member of the sixth generation of Gammarelli ecclesiastical uniform makers, making his family business one of the oldest in Europe.

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The shop's business card says, "Clerical Tailor Since 1789," which is pretty hard to beat on the longevity front.

The shop, behind the Pantheon in the heart of old Rome, is a source of pride for Romans and becomes rather famous every few years, or few decades, when a pope dies and a new one in sudden need of a wardrobe is elected by the College of Cardinals.

That pattern was interrupted last month when Pope Benedict XVI surprised the world with his decision to retire instead of leaving the job in a coffin. But the effect was the same: The Vatican put in an order for new robes for the new pope, whose identity will not be known until mid-March or later.

"A few days after [Benedict's resignation], they called and ordered three vestments," Mr. Gammarelli said. "We said, 'Thank you.' "

Why three? Because the dimensions of the new pope are not known. He could be S, M or L, so one of each was made. If he is a pasta-stuffed XXL, Mr. Gammarelli will have a problem.

All three are on display in the shop window. The gleaming white robes are made of satin-wool with white silk cuffs. The garment in the middle sports a red velvet, fur-trimmed mozzetta, the short cape that is worn over the cassock. The display includes red papal shoes. Each garment took three to eight tailors 31/2 days to make.

How much will the Vatican have to fork out for the garments and accessories? Mr. Gammarelli won't say. "We don't talk about prices," he says. "There is an order and there will be a payment."

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Indeed, Annibale Gammarelli hasn't stayed in business for more than two centuries by offering freebies.

The business was started by Giovanni Antonio Gammarelli under Pope Pius VI (1775-1799) and was handed down through the generations. The original shop opened near the Vicarage of Rome, to be near its clients. In 1874 it moved nearby, to its current location, and is thought to be the oldest shop in Rome.

It is fairly small, with old wooden shelves stacked to the ceiling with the finest fabrics. A discreet fitting room, decorated with religious objects, sits off the main room. The tailors' workshop – off-limits to the public – is upstairs.

Gammarelli is not the only clerical tailor in the Pantheon neighbourhood. Several others cater to lesser lights in the Catholic Church (the cheapest priestly garment starts at about $80 in these shops). But Gammarelli is the only one that has nailed the highest-end customer – the pope himself.

Mr. Gammarelli says the family knows for sure that it has dressed seven popes and is pretty sure it has done so for three others, starting with Pius IX (1846-1878), who set the now-familiar black-and-red dress code for cardinals.

The shop has clad most of the popes and cardinals since then. The glaring exception, much to the shop's disappointment, was Cardinal Wojtyla. "He used a tailor in Poland," Mr. Gammarelli explained.

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But when the cardinal became John Paul II, he kept the papal tailor tradition alive and switched to Gammarelli , becoming its most famous customer.

Editor's Note: An earlier version of this story incorrectly said Pope John Paul II was not clad by Gammarelli. This version has been corrected.