The earliest record is flatbread with cheese and dates. But there has been all sorts. For a while, a common base layer was lard topped with herbs, then the cheese on top of that.
Even now not all pizzas use a tomato base. And I'm not just talking about American pizzas that use barbeque sauce or something, pizza bianca ("white pizza") is a style that will forgo tomato sauce for olive oil, lard, or bechamel sauce.
If you think pineapple on pizza is controversial, I had a bechamel sauce and pear pizza in Naples. Kinda unusual.