For a long time, pizzas were associated with poverty and scorned by food writers.

In 1831, Samuel Morse described pizza as a ‘species of the most nauseating cake … covered over with slices of pomodoro or tomatoes, and sprinkled with little fish and black pepper and I know not what other ingredients, it altogether looks like a piece of bread that has been taken reeking out of the sewer.’

While on a visit to Naples in 1889, King Umberto I and Queen Margherita grew tired of the complicated French dishes they were served. Three sorts of pizza were offered to the queen: one with lard, caciocavallo, and basil; another with cecenielli; and a third with tomatoes, mozzarella, and basil.

The queen was delighted. Her favorite – the last of the three – was named Pizza Margherita in her honor.

• From the 1930s onward, a number of Neapolitans moved northward, taking their cuisine with them.
• When Allied soldiers invaded Italy in 1943, they so liked the pizza that they asked for it wherever they went.
• After the war, tourists became increasingly curious about Italian food, including pizza.
• In America, by the end of the 19th century, Italian emigrants had reached the East Coast, and in 1905 the first pizzeria was opened in New York City.
• Shortly after the US entered World War II, a Texan opened Chicago pizzeria. He offered the dish with a thicker crust and with more toppings, usually with cheese at the bottom and chunky tomato sauce on top.
• In the 1950s, the pizza became more domesticated. Frozen pizza was designed to be taken home and baked at will.