I know the modern (Naples) pizza didnt come until much later, but I've seen several references to similar foods being made in the Mediterranean area even before the founding of Rome. These are generally said to be flatbreads with toppings.
What I am really curious about is whether this was ever done in a large social setting in early Roman culture. It's common in the current day to serve pizza to large groups as the main or only course. Were the "pizzas" of antiquity ever served in this manner, or just one part of a meal made at home? Both?
I'm also curious how popular or even available such food was to soldiers. I've been trying to learn more about the actual daily lives of early Romans outside of major events, and not-quite-pizzas fascinate me for some reason. Thank you for reading my question, you folks give some great answers!
While I cannot claim to be knowledgable on the history of Pizza, I do know it's a 19th-century invention. You have to keep one thing in mind, the Romans did not even know what one of the main ingredients of pizza was. They did not have tomatoes.
Much like the Sandwich though, there were probably variations on the theme going back to antiquity. Putting food on bread, or dipping bread in a sauce makes it simply taste better, and fills you up faster.
Feasts were a big deal in ancient Rome, often accompanying games, celebrations of victory or as a sop to the citizens by individuals trying to curry favor. These would often last days and the amount and kinds of foods varied. Tables would be laden with everything from nuts and berries to exotic foods like Dormice stuffed with seeds. Though private parties could feature a main course, I really have never read an account in which a single type of food was served.
As for the legions, when on a campaign they survived mainly on journey bread, dried fruits/nuts and grains of various types. In garrison, they had access to other foods, fish, mutton and the sort. Availability and type would depend on location.