The tomato is native to the South American continent and was brought to Europe by the Spanish explorers, or by Columbus, who took them to Spain. It is said that Cortez found them growing in Montezuma's garden, but other historians say Columbus first discovered them on his voyages to find pepper and a new spice route.
Tomatoes were introduced to Europe in the early 16th century, along with corn and potatoes. The tomato and potato are related as they come from the Solonaceae family of plants, the nightshades. Because of these rather deadly relations, the potato and tomato (and aubergine/eggplant) were looked upon with suspicion. Even their Latin botanical name, Lycopersicum refers to Galen's description of the wolf peach which was poison used to kill wolves, that was wrapped in a delicious-looking packaging.
They were first grown for their ornamental value and the name, pomo d'oro in Italian would suggest that the original tomatoes were a golden-yellow. They were known in France as the Love Apple, pomme d'amour as it was believed that they were aphrodisiacs.
Pietro Matthioli, an Italian herbalist wrote in 1544 that the tomato was a poisonous plant, although he did mention that he had heard that some people ate them after frying them in oil. By 1623 there were yellow, golden, orange and red tomatoes. The yellow and gold varieties may have been one and the same, depending on how the author of a text perceived colours. There is mention of the large red tomato in 1700 which was probably an ancestor of the Mediterranean 'beef' tomatoes we have now.
They retained their mystique for many years in France where they were originally eaten only by the king and his court. In Italy, however, they were food for all, enjoyed by aristocracy and peasantry equally. They flourished in the region between Naples and Salerno and the first known recipe for Spanish tomato sauce, Salsa di Pomodoro alla Spagnola was written in a cookery book from Naples in 1692.
Clearly they were growing in popularity in Italy during this period as by 1762 Lazzaro Spallanzani was experimenting with ways of conserving them. He boiled them and then sealed them in containers, but it wasn't until the 19th century that food was canned more or less successfully. The first cans of condensed tomato soup were produced by the American Joseph Campbell in 1897. Now, of course, we know that the lycopene which makes tomatoes and other fruits red is released on heating, so canning helps. Lycopene is believed to help protect from prostate cancer and to increase the male libido and help with erectile dysfunctions, so perhaps the pomme d'amour really is an aphrodisiac of sorts.
It is believed that the Neapolitans made the first tomato pies (the precursors of the pizza) by adding them to yeast dough. By the 17th century, Naples had pizzaioli or pizza makers and tomato pies were sold on the streets of Naples. The Neapolitans were also adding the new fruit to their traditional dishes.
In the 18th century, Queen Maria Carolina the wife of the King of Naples, Ferdinando IV (1751-1821) had a special pizza oven built for her chef in the summer palace at Capodimonte and pizza with tomatoes were served to her guests.
The pizza Margherita was made in 1889 for the wife of the king of Italy, Umberto I (1844-1900). Queen Margherita di Savoia called Naples' most popular pizzaioli, Raffaele Esposito, to her palace, and he made three different pizzas for her. She preferred the one that now bears her name, made of tomatoes, mozzarella and basil, the colours of the Italian flag, red, white and green, so the pizza bears her name.
Italians don't actually use tomatoes in every dish, but they are very popular; when I was in the Marché region, people frequently had spaghetti with a plain passata topped with a sprig of basil, or a fresh tomato, cucumber and mozzarella salad with olive oil and fresh basil for lunch. (Passata is fresh tomatoes, peeled, sieved and heated then blended.) Dinner may or may not have contained tomatoes, but they were on the daily menu in some form or other.
Although we think of tomatoes and Italy, they are also staples in Greek and Spanish cuisine.