Pizza bianca, white pizza: https://en.wikipedia.org/wiki/White_pizza

There is also a relatively new series of Chef's Table: Pizza if you want to see some uncommon pizzas in a beautiful documentary.

Why wouldn’t it? At least a third of the menu in most pizzeria’s in Italy will be white pizza with no tomato sauce.

Oh, that surprises me.

It has to, since tomatoes were not discovered by Europeans until the 16th century.

Nowadays you can ask for white pizza.

There is no rule saying "Pizza" has to have existed before the 16th century...

Commonly speaking you need either tomato sauce or mozzarella to call it a pizza. Without either one, it would be called “pizza pane” but that’s basically flatbread and to be eaten as bread. Pretty rare to find a “pizza” without some sort of sauce to make it wet.

Depends on ingredients but some do not go well with tomato sauce. For example pineapple[0] + blue cheese would be better on white base or no sauce at all than on tomato one.

[0] Read it as pear or fig if you are Italian.

yes, you can do cuatro formagi or other white pizzas and they are pretty good.

Italian ortography is not as bad as the english one, but nonetheless is sometimes illogical. We have a useless lettere 'q' which is pronounced like the the hard c. 'Q' is used only before 'u'. So there some words that are written with "qu" and other with "cu" only for etymologyical reasons. The number 4 is spelled 'quattro'. The pizza with the four cheeses is 'quattro formaggi'.

To be picky, the general rule is that q goes before u only if u is followed by another vowel (qui, quo, qua), c is used in the other cases, but - of course - there are a few exceptions, the most common being "cui".

Okay, then it seems to be less the toppings than the "recipe ancestry" that determines what counts as Pizza. Otherwise flammkuchen would also count:

https://en.wikipedia.org/wiki/Flammekueche

> "recipe ancestry"

I think it is mostly about language. Pizza is loan word from Italian in German language in this case. So you may also say it other way around: Pizza counts as flammkuchen.

But it doesn't! I haven't heard anyone label one as a type of the other.

Yes, besides the toppings, for which there is no rule (there is pizza bianca without tomato, and there is pizza marina without cheese), I believe everybody agrees that pizza dough needs to be made with yeast or sourdough. Flammkuchen dough has neither.