Fascism at the best of times is a vague description. As a Marxist, I see fascism as being a reaction to a crisis of state brought on by a crisis of capitalism, as such, to argue that fascist states existed before capitalism wouldn't make sense. The goal of a fascist state then is to try and maintain capital as a mode of production, even if this is an unconscious and only historical role. Have there been dictatorial states and rulers before fascism? Yes, but I think to describe them as being fascist would be taking fascism out of the specifics of the 20th century. A nice pamphlet you can read would be Gilles Dauve's When Insurrections Die.

Well the Fascists came to power in Italy in 1922 and were the first fascist government anywhere. Fascism as an ideology only emerged in the early twentieth century.

Corporatism was actually not uncommon throughout history. It commonly re-emerges during wartime when nations force various interest groups (labor, business, etc.) to serve the production needs of the government. This is what the Fascists strived for, a government that directed the productive forces of the country for the national well-being of the people. Most wartime governments during either World Wars can probably be described as Fascistic.

But prior to Mussolini's Fascism in Italy there was actually a Fascist government in Fiume. It was established by Gabrielle D'Annunzio (the poet) who was originally trying to annex it for Italy. Mussolini and D'Annunzio were actually colleagues, and much of D'Annunzio's flamboyance and theatrics were adopted by Mussolini later.