The History of the Pizza alla Napoletana

The Pofokes Pizza alla Napoletana - "The Pizza of Naples"

... Pizza evolved into a type of bread and tomato dish, often served with cheese. However, until the late 19th or early 20th 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.

After the feedback of some readers, Artusi added a typed sheet in the 1911 edition (discovered by food historian Alberto Capatti), bound with the volume, with the recipe of "pizza alla napoletana": mozzarella, tomatoes, anchovies and mushrooms.

- Wikipedia

So, Artusi, whose cookbook is the oldest with a recipe for pizzas (all sweet, not savory), updated his 1891 cookbook in 1911 to include what he considered "The Pizza of Naples".