The history of pizza is long, complicated, and controversial.
The neapolitan word pinsa, from the Latin verb pinsere ‘to push, to press’, probably comes from Greek pita, word still used in Greece and in the Balkans.
The Romans prepared a focaccia with cheese, still common in the Middle Ages; the word pizza appeared for the first time in a document written in 997 AD in Gaeta. The evolution from the medieval focaccia to the pizza napoletana is not clear, in Napoli pizza but it was a popular food, especially among lower and poorest classes, in medieval and early modern times.
The original recipe do not include tomato sauce since tomatoes were introduced in Europe only after 1492.
But apparently, before pizza napoletana, there was pizza genovese!
Prepared for the first time in 1490, named pizza d’Andrea after admiral Andrea Doria, who loved it, exported then in France, where it was called Pizzalandereia and then Pissaladière, now a typical in Nice and dans la Cote d’Azur.
Pizza or Focaccia genovese, with onions, olives, cheese, anchovies
XV and XVI century sources describe a focaccia with cheese, basil, and black pepper, probably the first version of Pizza napolitana; tomato became part of the recipe in XVIII century.
Pizza became so popular that even the Royal House of Savoia knew it; in 1889 pizzaiolo Raffaele Esposito created a special one, named after queen Margerita di Savoia, to celebrate the newly introduced green-white-red flag.
And here’s Pizza Margherita, the queen of pizze!
(See also “I miss 100(and more) shades of pizza – 1” https://misshome.wordpress.com/2014/01/25/207-i-miss-100and-more-shades-of-pizza/ )