you're right, pizza HAS always been a working class meal.
ever since its invention in the 16th century by an unknown peasent, but it was made famous by none working class royalty.
The innovation which gave us the particular flat bread we call "pizza" was the use of tomato as a topping. For some time after the tomato was brought to Europe from the Americas in the 16th century, it was believed by many Europeans to be poisonous (as are some other fruits of the nightshade family). However, by the late 18th century it was common for the poor of the area around Naples to add tomato to their yeast-based flat bread, and so the pizza was born. The dish gained in popularity, and soon Pizza became a tourist attraction as visitors to Naples ventured into the poorer areas of the city in order to try the local specialty.
Until about 1830, pizza was sold from open-air stands and street vendors out of pizza bakeries. Antica Pizzeria Port'Alba in Naples is widely regarded as the world's first pizzeria. They started producing pizzas for peddlers in 1738 but expanded to a pizza restaurant with chairs and tables in 1830, and still serve pizza from the same premises today. A description of pizza in Naples around 1830 is given by the French writer and food expert Alexandre Dumas, père in his work Le Corricolo, Chapter VIII . He writes that pizza was the only food of the humble people in Naples during winter, and that "in Naples pizza is flavored with oil, lard, tallow, cheese, tomato, or anchovies".
The Neapolitans take their pizza very seriously. Purists, like the famous pizzeria "Da Michele" in Via C.Sersale (founded: 1870)  consider there to be only two true pizzas - the "Marinara" and the "Margherita" and that is all they serve. The Marinara is the oldest and has a topping of tomato, oregano, garlic, extra virgin olive oil and usually basil. It was named "Marinara" not, as many believe, because it has seafood on it (it doesn't) but because it was the food the fishermen ate when they returned home from fishing trips in the Bay of Naples. The Margherita is attributed to baker Raffaele Esposito. Esposito worked at the pizzeria "Pietro... e basta così" (literally "Peter... and that's enough") which was established in 1780 and is still operating under the name "Pizzeria Brandi". In 1889, he baked three different pizzas for the visit of King Umberto I and Queen Margherita of Savoy. The Queen's favorite was a pizza evoking the colors of the Italian flag - green (basil leaves), white (mozzarella), and red (tomatoes). This combination was named Pizza Margherita in her honor.
yeah, i watched channel special on pizza, but i copied and pasted that from wiki.