The true (maybe, sortof) Historie of Pizza is found here. (somewhat)

Pizza was a "po fokes" food.

Pizza is now a type of bread and tomato dish, often served with cheese. However, until the late nineteenth or early twentieth century, the dish was sweet, not savory, and earlier versions which were savory more resembled the flat breads now known as schiacciata.

Pellegrino Artusi's classic early twentieth century cookbook, La Scienza in Cucina E L'arte Di Mangiar Bene gives three recipes for pizza, all of which are sweet.

However, by 1927, Ada Boni's collection of regional cooking includes a recipe using tomatoes and mozzarella.

The term 'pizza' first appeared "in a Latin text from the southern Italian town of Gaeta in 997 AD, which claims that a tenant of certain property is to give the bishop of Gaeta 'duodecim pizze', "twelve pizzas", every Christmas Day, and another twelve every Easter Sunday,".

In 16th century Naples a Galette flatbread was referred to as a pizza.  A dish of the poor people, it was sold in the street and was not considered a kitchen recipe for a long time.

Before the 17th century, the pizza was covered with red sauce.  This was later replaced by oil, tomatoes(after Europeans came into contact with the Americas) or fish. In 1843, Alexandre Dumas, père described the diversity of pizza toppings.

In June 1889, to honour the Queen consort of Italy, Margherita of Savoy, the

Neapolitan chef Raffaele Esposito

created the "Pizza Margherita," a pizza garnished with tomatoes, mozzarella cheese, and basil, to represent the colors of the Italian flag.

He was the first to add cheese.

Thank you! chef Raffaele Esposito!

The sequence through which flavored flatbreads of the ancient and medieval Mediterranean became the dish popularized in the 20th century is not fully understood.

Source: Wikipedia

End Notes:

"The sequence through which flavored flatbreads of the ancient and medieval Mediterranean became the dish popularized in the 20th century is not fully understood."

Thankfully, we can eat the wonderful stuff without understanding it all!