On the Salita Santa Anna in Naples, not far from the Palazzo Reale, a modest restaurant called the Pizzeria Brandi has been serving various types of pizza in the same building for over 200 years. It first opened in 1780 as the Pizzeria Pietro e Basta Cosi (meaning "the pizzeria of Peter, and that's enough"), but eventually its childless owner, called simply Peter the Pizzamaker, transferred its ownership to Enrico Brandi. Enrico's son-in-law, a pizzaiuolo (pizza-maker) named Raffaele Esposito, managed the restaurant in June of 1889 when the shop got a visit from royalty. King Umberto I of Italy had assumed the throne upon the death of his father a little over ten years earlier; he and Queen Margherita had once lived in Naples and, as they were planning a trip back to the city, they decided to indulge themselves in the local cuisine.

Residents of the Mediterranean area had enjoyed rudimentary forms of pizza for centuries, if not millennia, before the existence of the Pizzeria Pietro, creating various dishes comprised of flat bread with toppings. When local cooks began to add tomatoes to the recipe in about the late 17th century, pizza began to take its modern form. The dish soon became a fad of central Europe; monarchs built outdoor pizza ovens at great expense, and Alexander Dumas mentioned it as a winter food in his work Le Corricolo in 1835.

Anticipating the royal visit, Esposito made three pies from which they could choose: the first was a traditional marinara, with olive oil, garlic, and oregano, and topped with anchovies; the second, a bianca or white pizza, with basil, pork fat, and caciocavallo cheese. Esposito believed garlic to be too gauche to serve to a King and Queen, so he created a patriotic third pizza, with tomato sauce, white mozzarella cheese, and basil representing the three colors of the Italian flag. Raffaelle Esposito and his wife, Maria Giovanna Brandi, personally transported the pizzas to the royal palace aboard a donkey-drawn cart.

The royals tasted of all three pizzas, but Queen Margherita especially loved the third version. Esposito immediately dubbed it the "Pizza Margherita" and wasted no time marketing his new flavor to any and all Neapolitan townspeople and visitors. On June 11, 1889, the office of the Queen sent Esposito the following letter, the original of which still hangs in the Pizzeria Brandi:

Dear Mr. Raffaele Esposito (Brandi),
I confirm that the three qualities of Pizza You prepared for Her Majesty the Queen were found excellent.
Sincerely Yours,
Galli Camillo
Head of the Table of the Royal Household

The new flavor was a rousing success, and ever since then, mozzarella cheese has been a staple of pizza everywhere, and tourists flocked to what was by then renamed the Pizzera Brandi to taste the original. One such tourist was Gugliermo Marconi, inventor of wireless radio, who visited in 1896 but complained that the cheese was too stringy; "Perhaps," his quick-witted waiter replied, "Marchese Marconi should have invented wireless mozzarella."

Links and sources:
The Pizzeria Brandi's home page, in Naples, Italy
"History and Legends of Pizza" by Linda Stradley, on What's Cooking America, retrieved April 27, 2012.
American Pie: My Search for the Perfect Pizza by Peter Reinhart, Random House Digital, 2003.
Naples at Table: Cooking in Campania by Arthur Schwartz, Harper Collins, 1998.